Watching that onboard with team radio's is pretty conclusive to me, I was a bit on the fence earlier as to why someone mid-pack would try to overtake the race leader.
a) Max said Ocon was pushing him, and Max knew he was on newer tyres.
b) Max would have seen the blue flags for Ocon/ Hamilton when they first exited the pits, and therefore known if Ocon got past him and slowed up, he'd get blue flagged again for Max.
A mid-pack trying to unlap themselves past a leader likely doesnt happen very often, but shutting the door on turn 2 like that after taking a defensive line into 1 was a bad call. Learning curve for Max.
Why? If Ocon passed Max, they are both on the lead lap, so no blue flags AFAIK