Apparently everyone wanted to go off the track in the same 30 seconds. Grosjean and Hulk off, Kvyat coming very very close to going off.
Kvyat looks really nervous and slightly dodgy. Some real issues in terms of getting in the way on track, very poor when off the pace and being aware of others, complaining of having too much to do.
With that replay, Grosjean screwed his car pretty badly, left rear suspension looks like it broke, he broke, rear twitched maybe hit the wall before the corner and sent him off into the gravel track. Possible the suspension failed causing the contact with the wall as the rear did seem to suddenly change direction causing the contact.