"Nothing good ever happens in warm-up"...etc etc.
The main cause of this is everybody piling out all at once, all at different speeds (some taking it easy, some not so much) - it surprises me that we don't see more clumsy contact like this. It looks like van der Linde in the Lexus was more on the 'taking it easy' side, perhaps getting the brakes up to temps and keeping his distance from the cars in front of him, hence the sudden braking.
So, fair play to de Vries for accepting responsibility but it wasn't 100% his fault.