We didn't hear much of the McLaren radio during the race, a pity as I think it might have been rather interesting.
One clue is that MW has said that they were initially going for 2 stops, while Lewis has said that it was always his intention to do 3 stops.
Another clue is that Jenson did another lap, after he got the call to pit, at the end of the first stint.
My guess is that Lewis' side of the garage were saying 'we have to pit now to cover Rosberg' while Jenson's side were saying 'it doesn't matter, Rosberg will be making an extra stop, we have to make a longer stint now to minimise the final stint on primes'.
I suspect that Jenson himself may have been heavily involved in this argument, and this might have been the distraction which led to Jenson going into the wrong pit.
In the 2nd stint, it's clear that Jenson still thought that he was on a 2-stopper. He drove just fast enough to keep Massa behind him, and he must have been very surprised and disappointed when this turned out to be a very short stint. At this point, I assume that Lewis' side of the garage had won the argument.
In the second half of the race, Lewis drove like a man who felt he was finally on the right strategy, while Jenson drove like a man who felt his race had been fatally compromised.
So why didn't McLaren just give both drivers the strategy they wanted? Well, I think they might have anticipated some criticism if they pitted Lewis first, and he then used the undercut to get ahead of Jenson. Especially after they have made a big thing of equal treatment for their drivers, in contrast to you-know-who.
Personally, I don't think they should have let this consideration interfere with running the best possible race for both drivers. If Jenson ran a 2-stop and it didn't work, well they would have learned something. And in fact a properly-timed 2-stop might have worked better for Jenson anyway.
Edited by BillBald, 20 April 2011 - 23:31.