Continuity mistake: Daffy takes down a gun from the mantle, but when Daffy points it at Bugs in the next shot, you can still see the gun on the mantle.
Continuity mistake: When Bugs is performing his shooting stunt in the saloon, you can see the entrance behind Sam has nothing between it. When Sam tells Bugs he's missed, we cut to Bugs who says "Wait!" and then return to Sam, and this time there are doors between the entrance.
Continuity mistake: When Witch Hazel tries to attack Bugs with her meat cleaver, Bugs runs off to the castle and you can see the cleaver in the ground. But when she calls for her broomstick to come over to her, the cleaver has gone.