The forecast for Friday was ceaseless rain, but it turned out rather better than that. Certainly it was wet at first, and the first practice session began on a very damp track, but in the closing stages everyone was able to switch from intermediates to slicks, and right at the end di Resta’s Force India set the quickest time, followed by Button’s McLaren, Grosjean’s Lotus, Alonso’s Ferrari, Räikkönen’s Lotus and Ricciardo’s Toro Rosso. That the session didn’t really mean very much was evidenced by the absence from the top six of the Mercedes (Rosberg seventh, Hamilton 16th) and the Red Bulls (Vettel ninth, Webber 10th).

The morning was reasonably straightforward, although Maldonado wiped the nose off his Williams, and Hamilton took a hard ride over the chicane when he misjudged the speed of cars ahead of him heading into the pit lane, and had to take avoiding action.

Very much against expectations, the afternoon session was run in dry conditions throughout, which allowed the drivers to try Pirelli’s revised tyre, which will make its competition debut at Silverstone: reactions were generally favourable. Alonso wound up fastest this time, followed by Hamilton (always super-quick in Montreal), Grosjean, Webber, Rosberg and Massa.

Many expected the main excitement of the day to come from the team principals’ press conference at the conclusion of practice, for scheduled to appear were Stefano Domenicali (Ferrari), Martin Whitmarsh (McLaren), Monisha Kaltenborn, Christian Horner (Red Bull) – and also Ross Brawn (Mercedes) and Paul Hembery (Pirelli). The sniping against Mercedes, following the controversial, three-day, 1000-kilometre Pirelli test at Barcelona, had carried over into the Montreal paddock, and some anticipated public confrontation between Brawn and, particularly, Horner, for Red Bull have been by far the most vocal critic of Mercedes.

Not long before the conference Hembery, on the advice of Pirelli lawyers, withdrew from it, but if proceedings began predictably enough, with Horner stating yet again his belief that Mercedes had broken the rules by taking part in the test, the event quickly turned into a bit of a damp squib. Brawn insisted that it had been a “private test rather than a secret test”, that it was very much a Pirelli test, organised and paid for by the tyre company, and he said that the decision for Mercedes to take part in it had been his, and his alone. No, he said, it wasn’t a particularly pleasant position to be in, but he had been through similar situations in the past: “That’s Formula 1, isn’t it?”

To most questions, Ross was reluctant to go into any detail in his answers.: “As you know, there is to be an FIA Tribunal, which will meet some time in the next few weeks, and make a decision about this. There the full facts will become known…” When they were, he said, he was confident of a favourable outcome for Mercedes, and he said it several times in the course of the conference: if some journalists present were trying to goad him into saying more than he intended, they did not succeed.

On Thursday the weather forecast had been terrible for Friday, mixed for Saturday, then pretty good for Sunday, but now the experts are predicting a 60 per cent chance of a wet race, and Button, for one, is hoping they are right: “We’re going in the right direction,” he said of McLaren’s progress, “and definitely closer to the pace than we were, but in the end it’ll be the usual cars at the front in qualifying, and our best hope is for wet – or, even better, mixed – conditions for the race. This place is always unpredictable…”