The problem is once again he has no idea if Iida knows who he is. Should he say something? Shouldn't... shouldn't they be stopping the corpses? Even as polite as they are, they're still decomposing corpses and they're seriously freaking people out here.

"Ah... hey?"

Yeah, that's a good start. It leaves plenty of room for Iida to respond to him without letting him know Izuku knows him.