From a purely observational standpoint, Zhou had a terrible start off the line. He was getting passed from those behind him; I think he was still accelerating / maneuvering to get position when the pack was braking for the turn.
Zhou was a clutch thing that was probably human error. Released too quickly, anti-stall kicked in, had to engage again, and everyone passed him. He the. Clipped Ricciardo, destroyed Gasly’s car and Ocon’s spine.