In the beginning when Jake receives all of his belongings back after being relesed from prison, one of the items is a broken Timex digital watch. But Jake continually looks at his watch, i.e. he looks at his watch and notices they're late for their big gig at the end of the movie. Does he replace it sometime we just miss it?

Evey time they show Elwood's apartment window, a train goes by.

When Jake jumps the bridge after picking Jake up, it's much farther down than it would've been at that time.