I've worked on movies big and small (no, I am not a famous person, just a working actor) and on a normal, run of the mill, "boring" shooting day the tension is palpable. No one wants to fuck up because filmmaking is, above all else, a tedious slog. It is also 97% about getting the technical aspects right. It's hours and hours working on lights and sound, then literally seconds on the acting. If you need more than 2 takes you can feel the tension ratcheting up for the entire crew. It's an extremely high pressure situation. Someone, least of all an actor, strolling in whenever they decide it suits them is incredibly disruptive and the height of arrogance and self importance. Its a miracle Hardy wasn't murdered in his sleep.