"You'd let me fall, then? You are no gentleman, James Bond."
Despite being sore from being banged around during the evacuation, and seeing things he'd rather like to forget, things turned out all right in the end. And here was Bond, chatting with him in a rather friendly way, if he says so himself. There's no reason whatsoever to not be in a good mood.
Which means he's still smiling, feeling a bit warm at the back of his neck as he finishes off his drink.