It is not possible to go into a blow-by-blow analysis of what happened in the race. That is probably not necessary anyway. But I would like to posit that Button took this sensational win not despite his six tyre stops, but partly because of it. The mantra in wet races is always to be on the right tyre at the right time. Get the calls correct and you can have a per-lap advantage measured not in tenths of seconds, but in whole second chunks that leave rivals floundering.

Add that to the relatively short pit lane in Montreal, and making decisive tyre calls quickly was always going to be a key factor in this race. At every change-over point, Button was amongst the earliest drivers to act. Early in the race, after his collision with team-mate Lewis Hamilton, he was the first to try the intermediates. Even after taking the drive-through for speeding under the safety car, within two laps, without anyone else having spun or stopped, he was ahead of where he had been in the safety car queue!

This meant, by the time the rainstorm came, Button had made a net gain on the inters before switching back to the full wets. On the other hand, those who responded to Jenson’s pace too late and put on inters just as the rain fell, such as the Mercedes drivers and Fernando Alonso, found themselves in a double-jeopardy in which they had lost time by having not switched to inters earlier, and then wasted a pit stop’s worth of time for no perceivable gain.

If there were things that you could say Jenson won this race in spite of, it was the drive-through penalty for which there was no-one else to blame, and the collision with Alonso and the resulting puncture which put him to the tail of the field. But from there his blistering speed on inters and then on the super-softs, aided by Jenson’s legendary sensitivity in these conditions and the wet set-up on the McLaren which had hindered them in qualifying, made the Englishman an irresistible force.

It is arguable that had he not had these setbacks, he could have been in a position to challenge for the lead a lot earlier than the last lap. Nevertheless, the fact is that in the last ten laps, he passed three cars for the win. His move on Mark Webber was a miraculous piece of split-second car control. He made a first-time DRS-assisted pass on Michael Schumacher without fumbling the last chicane as Webber did. And his pressure on Sebastian Vettel forced the German into his last lap mistake.

Of course, the win was not without controversy after the contacts with Hamilton and Alonso. Both were racing incidents. With Hamilton, it’s not quite true to say that Button was merely taking the normal racing line. He clearly looked in his mirror and then moved left. Whether this was because he didn’t know where Hamilton was and decided to start taking the usual line, or because he was trying to block Lewis, is unclear. The problem was that Lewis had the run, but decided simultaneously to go left into a shrinking gap.

With Alonso, Button dived inside at turn 3 from a long way back, but he had actually not only got fully alongside, he had put his nose in front. It was Fernando’s choice to concede or fight, and he chose to fight by going deeper to take a wider line into the corner, which is what put the Ferrari’s front wing back ahead. Usually when a rival has got fully alongside, a collision is the defending driver’s fault, but given the nature of the right-left chicane, Alonso was probably entitled to try standing his ground.

So it was not a perfect performance by Button by any means, but he has deposed his team-mate from 2nd in the championship. After his awful Monaco weekend, more collisions ending in a DNF was not what Hamilton needed, and it only gave added ammunition for his critics - perhaps unfairly so. As I have said, the clash with Button was a racing incident when both McLarens decided to go the same way. Hamilton’s contribution was also in his refusal to back out when it became clear the gap was closing.

The earlier incident with Webber was more clear-cut. He had failed to get fully alongside the Red Bull, Webber noticeably straightened to give him room, and he still understeered into the Australian. It is surprising that Lewis did not receive a sanction for that. But in one sense that is probably a good thing as it means he is not compromised at Valencia, where what he really needs is simply a clean, fast, effective weekend. In F1, you’re only as good as your last race, so a good performance will put the critics off his back again.

Vettel will undoubtedly have felt massively disappointed to lose this race in the way that he did, having once again not put a foot wrong in qualifying and for the whole of the race up to that point. With every safety car restart he had judged things to perfection, and on every first lap after a restart he had been able to pull out a gap, which has been his hallmark this year. The buffer always gives him the advantage of being able to respond to others’ tactical moves.

But in the closing laps Sebastian was clearly getting flustered at being reeled in by Jenson. His response was to go into over-aggressive mode which was not making him any faster. In fact, on lap 69 he had already put his right wheels onto the damp going into turn 6 but he had got away with it. The next lap he got caught out. This year, when he’s been doing his own thing, he’s been perfect, but this last lap error only casts doubt once again on his ability to handle pressure in a genuine battle situation.

A podium for Webber after suffering KERS issues on Saturday, starting 4th, being turned around by Hamilton and also having a downshift problem early on was a good result adding to his solid if slightly underwhelming start to the season. It was clear he wasn’t getting great traction out of the hairpin, which often made him try too hard at that corner. Being passed by Schumacher there on lap 42 was a telling moment because it left the Red Bull having to pass the Mercedes later on in the race.

Without doubt, this was Schumi’s best race of his comeback that deserved a podium spot. You can’t say it was just because of the conditions; there have been wet races, such as China last year, in which Michael really struggled. But on this day in Montreal, it felt as though Schumacher saw an opportunity and his car body language suggested that he believed he could make the difference. It just goes to show that his performances in the last 18 months really have been about confidence as much as anything else.

And make a difference Michael did, especially in the second half of the race. Whilst he did err in going onto inters too late the first time, he didn’t make the same mistake on the restart, being one of the first to put inters on. Within two laps he was back up from 18th to 8th, then took Webber and Nick Heidfeld before clearing the squabbling Kamui Kobayashi and Felipe Massa is a masterful moment of opportunism, and he held his own in the last ten laps despite falling from 2nd to 4th due to lack of top speed.

Comparing his race to that of Nico Rosberg is interesting. After the red flag restart, Nico went to inters two laps later than Michael and paid the price. He found himself stuck in the midfield battling the likes of Adrian Sutil and the two Williams. Then he was one of the last to switch to dries, and found himself being passed by the likes of Jaime Alguersuari who had done so earlier. Late-on, in still trying to clear the pack, he hit Kobayashi, lost his front wing on the last lap, and dropped out of the points altogether.

One of Nico’s best traits over the years has been consistency, but generally he has erred towards caution and that is not enough under this year’s rules where quick-headedness is more important, and Canada showed up that weakness. For the first time since Michael’s return, he has drawn level with Nico on points (and is ahead on count-back), and it will be fascinating to see if Schumi, lifted by this performance, can really believe that he can still Do It in the dry. If so, keep a close eye on the intra-Mercedes battle.

There were two other drivers who should or could have featured in the battle for the podium in the closing stages. The first was Massa, and his too was a story of a driver rediscovering self-belief. He had been excellent in qualifying and had almost made it onto the front row. He was faster than Alonso in the early stages and, when Fernando made the mistake of switching to inters too late, Felipe did not follow, but after the restart got trapped once again, this time behind Kobayashi.

In other words, the story of Felipe’s race was of pace that he couldn’t use. It would have been interesting to see if he could have challenged Vettel. Of course, his race unravelled when he switched to dries and then hit the wall dodging the slow Narain Karthikeyan in a moment of bad luck that was no-one’s fault. But even then, in the closing stages he had the pace to clear the whole midfield pack and pip Kobayashi on the line. His speed didn’t reap its deserved dividends, but it ought to have given Felipe much confidence.

That could also make the situation within Ferrari quite interesting if Felipe - coming into Valencia where he dominated in 2008 - can also find an upsurge in pace at a time when Alonso may need the team to pull behind him as they did last year. His DNF after a troubled race which saw him slower than Massa in the early stages, go for inters too late, and have to queue behind Massa in the pits for inters after the restart, leaves him 32 points behind Button and 92 behind Vettel.

The other man, interestingly, could have been Paul di Resta in the Force India. Before the red flag the rookie had, apart from one off, made exceptional progress and, having not pitted for tyres, was 6th during the stoppage. Then, after the Alonso safety car, he was 5th ahead of Schumacher, pressing Heidfeld, and looking capable of joining the Massa-Kobayashi stoush. He ruined his chances with his half-hearted lunge on Heidfeld which broke his front wing and earned a drive-through penalty.

It seemed unfair that he should have to take a penalty when the Renault suffered no damage and it was the Scotsman’s own position that was compromised. But it had been yet another weekend in which the newcomer had completely had the edge over team-mate Sutil (although Sutil is ahead in the championship, 8 points to di Resta’s 2). Having said that, the German was headed for points when he became the first to put on dries, 5 laps earlier than anyone else, and landed in the wall.

Heidfeld eventually became unstuck behind Kobayashi, hitting the Sauber when Kamui slowed at turn 2 having got off the dry line, but it was really the first time either Renault driver had put a foot wrong, in which both had run in the points, often line astern, almost all afternoon. Vitaly Petrov finished off where Heidfeld couldn’t and came home 5th. It is interesting to think that he was amongst the few drivers not to err all race, when last year in such conditions you would have expected to see him flying off the road.

But that’s what you get from the two Renault drivers this year - solid but unspectacular performance, not enough to bring home the mega results but sufficient to keep the points tally ticking over, such that both Petrov and Heidfeld are ahead of the Mercedes drivers and Vitaly is only one point behind Massa. The Mercedes men, in turn, are only one point ahead of Kobayashi in 11th, before a 17-point gap back to Sutil. It shows that the top 11 men are doing the bulk of the points-scoring this season.

Kamui added to his tally with his 7th place, but having been 2nd during the red flag and having held onto that place until lap 51, to drop down to 7th would have been something of a disappointment. But in truth the Japanese driver had not really been on the pace all weekend - he was struggling to get out of Q1 initially - and his usual method of not rushing to make a tyre stop actually hurt him in Canada. Generally he was one the last to in at every change-over point and others had stolen a march on him in the meantime.

He may have been able to hang on for 5th but at the final restart he slid wide off the dry line in lapping a Virgin, and conceded the place to Petrov. Meanwhile, it was a creditable effort by Pedro de la Rosa filling in for Sergio Perez at short notice, and the Spaniard could have joined Kobayashi in the points had he not clipped Button on the restart after the red flag, required a nose change, and then got stuck momentarily in first gear. The best he could do from there was catch back up to the tail of the midfield pack.

Both Toro Rossos scored, the first time that has occurred this season, and that was particularly encouraging for Alguersuari after another ragged qualifying that saw him eliminated in Q1 and then start from the pit lane. But what eventually got him ahead of team-mate Sebastien Buemi was that he did not pit for intermediates just before the rain came, whereas the Swiss driver did. After the restart it was a matter of keeping their noses clean when others did not.

Amongst those who did not were the Williams drivers, following on from the Monaco heartbreak for Pastor Maldonado a fortnight earlier. The Venezuelan continued his recent turn of speed, out-qualifying Rubens Barrichello again, which shows that he may well be growing into this F1 caper. But it was the more experienced Barrichello, also a wet weather specialist, who led the way on race day, switching to inters early enough before the rain to get an advantage from them whereas Maldonado left it too late.

That gave the Brazilian track position ahead of his team-mate for the rest of the afternoon until the final restart, when Kobayashi’s off-track moment caused a concertina effect which did for both the cars from Grove. Barrichello lost a load of positions, and Maldonado hit Rosberg forcing a nosecone change after which he promptly spun off. The best Rubens could do was salvage another 9th place in the end, sandwiched by the Toro Rossos. Points are points, but only 4 points after 7 races is hardly what Williams expect.

Lotus were unhappy post-race, and rightly so, that they had failed to capitalise on all the chaos whereas their rivals did. Fact: in the early stages, both Jarno Trulli and Heikki Kovalainen were battling the likes of Buemi and de la Rosa. But their races were destroyed when both pitted simultaneously when the rain came, and a delay in Kovalainen’s stop meant both cars dropped to the tail of the field. Such is the risk when you pit both cars together. To add insult, Heikki retired shortly after the stoppage.

Trulli should have been able to finish as the best of the new teams, but an unscheduled late stop put paid to that. The trouble for Lotus is that an HRT finished 13th, matching Lotus’ best results this year. Assuming Lotus don’t quite have the pace to score points in the dry, the battle for the all-important 10th place in the constructors’ championship will come down to who can do the best in the two or three chaotic or attrition-filled races that may lie ahead this year. This result has put Lotus in real danger of losing out.

In contrast, it has put HRT in with a real shot of snaring that 10th place. For all their limitations, they have shown some real racing savvy this year, backed by Vitantonio Liuzzi who is revelling in the no-pressure atmosphere. Tonio excelled in qualifying once again, and spent most of the race in a titanic fight with the Virgins and his team-mate. Karthikeyan’s post-race penalty for jumping the chicane in passing Timo Glock meant he lost the 14th place that would have been an added bonus for the Spanish team.

Virgin keep looking as though they are on the verge of stringing something together only to fall short and end in disappointment. It started with Jerome D’Ambrosio not posting a time within 107% in Q1 despite it being his fastest time of the weekend, but still being allowed to start. On one view this made a mockery of the 107% rule. On the other hand, the fact that the Belgian was able to mix competitively with his direct rivals on race day vindicated the stewards’ decision.

D’Ambrosio also incurred a drive-through penalty, of course, for switching to inters before the safety car had pulled off after the restart, which was a critical misreading of the rules by the Virgin crew. The drive-through may have been a mandated penalty, but arguably it was no more than a rap on the knuckles. Such was the advantage he had gained by switching to inters and making a free stop behind the safety car, even after he took his penalty he was still ahead of those who had stopped legitimately.

And so that was two let-offs for the team in red and black, but there was no reprieve towards the end for Glock, who is of course a Montreal specialist having scored points there on his F1 debut and also taken a 2nd place in Champ Car. After Lotus’ self-destruction, he led the battle of the tail-enders, only to flat-spot his front tyres and be overtaken by Liuzzi, Karthikeyan and his team-mate. Had he been the one to take the 13th place on offer, then it would be Virgin rather than HRT now posing a threat to Lotus.

Finally, the Canadian GP was not exactly a shining example for all forms of officialdom. It would appear as though a standing start in wet conditions is now a thing of F1 folklore; a safety car start has become the norm. Notwithstanding the limited experience of Pirelli’s wet compounds, there was not enough standing water to warrant a safety car start first time around, nor four laps before the field was released. It also goes without saying that the length of time after the stoppage behind the safety car was simply ludicrous.

Many have also criticised the stewards for the number of investigations that were announced for just about every incident during the race and suggested that they should be more lenient towards racing incidents, especially in such difficult conditions. I disagree; the threat of an investigation is a useful deterrent against F1 becoming a wheel-banging, bump-and-grind form of motorsport, but an investigation doesn’t necessarily mean a penalty. An investigation is exactly what that term says.

I have already said that the penalty for di Resta was too harsh, but post-race the only penalty dished out was to Karthikeyan for illegitimately gaining places. No other sanctions were handed out, which shows that the stewards were using common sense. I see no harm in announcing an investigation, especially ones that will take place after the race. It allows for procedural fairness and proper decision-making taking all the evidence into account. It is much better than handing out a raft of penalties during the race.

It was, however, a sub-optimal race for the Canadian marshals. Despite the incidents one can readily expect at the Ile Notre Dame, the marshals and recovery crew seemed rather unprepared. McLaren were rightfully shocked at the way Hamilton’s car was handled and brought back to the pits, hanging and swinging on straps rather than being placed onto a flat-bed truck. It was in stark contrast to the renowned professionalism and efficiency of the Monaco marshals in the previous race.

There was no greater example than when the marshal slipped and fell twice recovering debris from the Heidfeld-Kobayashi incident, to almost be run over first by Kobayashi himself and then by Petrov. The marshals had no business running onto the track before the full safety car queue had formed. There were only a handful of cars behind the safety car; clearly there were more cars that would shortly be coming through at not inconsiderable speed to join the crocodile.

Furthermore, they did not appear to be properly dressed for the job; from the look of the not-very-sporty trousers and (certainly not-very-grippy) shoes, these fellows looked more like they had been plucked from a trendy Montreal restaurant rather than being ready for action. At F1 Rejects, we like our moments of mirth, and so the stumbling marshal gets the "Reject of the Race" award, but in all seriousness, this was a needlessly close shave, and it is only good fortune that meant he did not get badly injured.