I've never seen anyone walk but I have seen folks emote between pulls or must have had their in character stuff macro'd because they managed to keep it going and keep the dungeon going. So I don't usually mind. And good RPers will contain this sort of thing to a party that has agreed to it all. If they're doing it in a way that will intentionally inconvenience others with random people, they're just griefing and trying to use RP as an excuse.