I was thinking of "The 37's" last night oddly enough, though I've not seen it in years. There's a scene where all the ancient survivors have been thawed out, and the focus is on Earhart and Janeway (I think it's Janeway) as a tricorder or something is activated. One of the non-speaking extras directly behind them, a burly bearded guy (Memory Alpha calls him a Scandinavian fisherman), overplays his reaction to the device by jerking his arms slightly, drawing attention away from the main actors. If I'd been the director I would have fired him on the spot, he ruins the scene for me.