I’m pretty sure every Celebrity Jeopardy sketch SNL ever did ended with Will Ferrell’s Alex Trebek being in an unpleasant mood. The comedic objective was basically to watch him get more and more worked up, but apparently, during one particular sketch, he got so worked up that fellow cast member Norm Macdonald was convinced Ferrell was legitimately mad in real life.
The sketch in question is the one where Macdonald, playing Burt Reynolds, shows up wearing a giant cowboy hat. At the very end, when Ferrell’s Trebek can’t take it anymore and signs off, Macdonald’s Reynolds takes the cowboy hat and roughly puts it on the host’s head. Seemingly incensed, Trebek turns around and starts yelling at Reynolds before it cuts away.