F1 Fanatic

Canada 2011, lap 69 out of 70, Force India crashes in turn 8/9 (the third chicane).
Vettel and then Button are seen to sail through the yellows, and at the
end of the lap Button goes purple (fastest lap)

My question is whether might have been flagged by the stewards or even penalized.. As DC keeps commenting on the BBC, drivers must be
seen to visibly slow under yellows. So how can button go purple ?

…which is especially likely given the circumstances of that moment: the track was drying and pretty much everyone was going quicker (see the lap times here), and Button was able to use DRS on that lap, where he hadn’t on the previous lap. Recall also there were two DRS zones at Montreal last year.

Thankfully the stewards do apply some degree of common sense in these situation, so as long as the driver didn’t set a purple sector, or would have gone faster yellow or no yellow, there wouldn’t be a penalty.