Continuity mistake: When Sam (dressed in a suit of armour) tries to cut off Bugs' head with an axe when Bugs reaches the top of the stairs, he falls off the stand with the axe, but when he falls down the stairs, the axe is nowhere to be seen.
Continuity mistake: When Sam returns to his seat after giving Bugs the pepper pot during the lunch scene, the items on his plate change position between shots.
Continuity mistake: When Bugs asks Sam to pass down the salt whilst he is eating at the dinner table, the salt and pepper pots next to Sam change position between shots.
Continuity mistake: When Sam knocks on the bathroom door, he says "Get outta there!" and Bugs opens the door on him. You can see that Bugs opens the door outwards when this happens, but when Sam barges in on Bugs later on, the door opens inwards.
Continuity mistake: When Sam runs into the closet after Bugs asks him for some olives, he opens the door and you can see the back of the door is completely clear, but when we see Sam ranting and raving, panels have appeared.
Continuity mistake: When Sam takes the salt shaker to Bugs, he places it on the corner of the table, but when Sam walks back to his chair, the shaker has disappeared.