Revealing mistake: In the scene where Al and his Dad (both played by Ed O'Neill) are sitting on the couch side by side watch the lines of the cushion in the middle. Every time one of them moves you can see where the two separate shots are overlaid. (00:14:15)
Revealing mistake: At the park when Al hits the rich man, he goes down like he was knocked out. Soon after, Seven punches the kid. In the background the rich man is actually sitting up on his side and he looks at Al and Seven, then as the camera pans towards him, he lies down on his side like he is passed out again.