The VSC was confirmed just as the leaders were getting close to the pit entry. It was early enough to offer the advantage of a very time-cheap pit stop, as a new set of hard-compound tyres would comfortably get to the end from there. Perez was called in about 1s too late – after he’d already passed the painted lines which define the pit entry lane.
Leclerc by contrast was already in that lane even before his team was telling him to pit. Verstappen was told to do the opposite of the Monegasque and so stayed out.
Potentially, this had just won Leclerc the race. Perez later implied his irritation of not being advised soon enough that the pit window would be open if there was a VSC, meaning he wasn’t prepared for the sudden call.
With the pack at VSC speeds, the pit stop loss is around 10sec less than a stop taken with the field at full racing speed. The Red Bulls were 1-2 for now, but Leclerc in third, all his tyre changing done for the day, was only around 9sec behind and they still needed to make their stops.
That’s indeed how it panned out. After both Red Bulls had made their stops Leclerc was leading the race by 13sec. There were 43 laps to go. Yes, the Red Bulls were on fresher rubber – and Verstappen was now ahead of Perez – but they would need to be careful in how much of that rubber they used up in closing down that big gap, so as to still have more rubber than Leclerc by the time they arrived on his tail – if they ever did. Given also that it had already been shown that the Red Bull’s end-of-straight advantage wasn’t necessarily enough to get it past even with DRS, it was by no means a done deal that Leclerc could not have stayed ahead. Maybe, maybe not.
Could Perez have won?
Had he stopped under the VSC, yes. He had track position over Leclerc and Verstappen. If Max had still stayed out, he could not have overcut ahead because of Perez’s time-cheap stop. Leclerc also would have still been behind – he was coming in regardless of what Perez did – and with the Ferrari subsequently retiring it would have come down to Verstappen chasing Perez down on fresher rubber later on. Could he have held on?
Once Perez missed the pit entry, he was doubly doomed for not only was he on a less advantageous strategy but it also left him on rear tyres which had not reacted well to being pushed hard on full tanks for the first few laps, then suddenly cooled under the VSC. This can cook the rubber, making it hard and brittle.