The missed penalty had no effect on that game. We equalised about 5 minutes later anyway. And no it's not normal to wait until the game is literally over, I think he'd just lost the plot, he knew Mirallas wasn't getting a kick.
I agree about the mentality of the squad, but it was his own squad that he'd moulded and his own mentality had rubbed off on them. It wasn't a coincidence that we couldn't defend and were devoid of ideas to break teams down under him. A chunk of that squad have been binned off already and there's just a few left to see out the door come the summer, thank god.