Audio problem: After the nightmare, Elmer rushes back to the log and pieces of his torn-up contract blow around in the air. At this point, you can see Bugs mouthing his catchphrase "Ehhh, what's up, doc?" but there is no sound.
Continuity mistake: When Elmer is in the log, he puts out his hand to make sure he is on the ground and you can see there is a rock by the log. When Elmer breaks up his shotgun in front of Bugs, there is now no sign of the rock.