He had the inside line and decided to try and squeeze Button off the track when he pretty much had track position, resulting in contact. Rather a bizarre incident.
Looked absolutely side by side on entry. Button left the gap, Grosjean took it but then Button decided to turn in as if he was pretending Grosjean wasnt there
I'd have to watch it again but from what I saw, Button left the gap and Grosjean decided he wanted more than his fair share, Button turned in in order to take the corner and the predictable occurred. Good overtake Grosjean on Massa, see, you can do it properly.