Continuity mistake: In the beginning, when Billy is talking to the bum (who later turns out to be Tawny), the bum has a glove on his right hand. When he reaches his right hand out to Billy and Billy gives him a subway token, there is no glove. It's back in the next shot.
Continuity mistake: When Charlie is coaching Sam in baseball at the beginning of the movie, they get on the road and he beckons to him. In the first cut, people in the background change (most obviously, a guy is crossing the street behind him, but vanishes in the second shot). (00:07:45)
Continuity mistake: At the end of the movie, when Robert has been resurrected as a tricycle, the bell and ribbon keep moving back and forth from the right handle bar to the left one.