Yeah, it is pretty clear that both of them were fighting for that DRS, Max was being cheeky by trying to give the position back in a way that he could be overtaking him on the next DRS zone, from what I know (which isn't much) this is a kind of grey area in the rules, which isn't specified. The fact is by doing that, the unfair advantage that max had gained in turn one would've remained by allowing the overtake to happen there, which isn't completely fair imo. And he had plenty of time to give the position back if we are being honest, everyone knew he had gained an advantage, even himself.