Charlie Wants an Abortion - S1-E2
Continuity mistake: At the beginning when they're making fun of Charlie, Mac is holding the ball against his body. In the next shot he's holding it up in his hand. It switches back and forth Then he's no longer holding the ball.
Continuity mistake: In the waiting room of the hospital, you can see over the shoulder of the woman, and she's reading a magazine, but when the camera angle changes, she's holding a newspaper. It switches back to a magazine in other shots of her.
Continuity mistake: While Mac is holding the picture of himself to Dennis & Dee, towards the end of the scene he is holding the picture with one finger around the middle on the top edge. Dennis then says "You're going to hell". The next shot he is holding the picture by its side with two fingers.
