Revealing mistake: During the animation of lighting your cigarette, when Arthur brings his left hand up to cover the flame, his thumb passes right through the cigarette.
Continuity mistake: After passing out drunk, Arthur wakes up on the floor with a beer bottle on the ground next to him. In the cut scene, he stands up and the bottle is still on the ground as he's standing. Then in the next shot, he looks at his hand and now the bottle is in his hand.
Continuity mistake: After being attacked by a creature of some sort, Arthur wakes up a second time with a bottle in his hand. Angry, he throws it as hard as he can, and in the close-up, he is pulling back his right arm to throw. But in the next shot, he's swinging his left arm to throw the bottle.
