Revealing mistake: When the officer on the bike chases Wilee, the door to a taxi opens and the officer collides with the door. You can see that the window had been removed from the door to make sure the actor doesn't get injured. It certainly wasn't rolled down because the frame isn't even there. (00:18:00)
Continuity mistake: Whilst riding through New York at 5:17pm, Wilee drives past a silver Ford. As he does this, a taxi is visible behind it. But when the shot cuts, the taxi has suddenly become a black car. (00:07:50)
Continuity mistake: When Wilee phones Manny early on in the movie, Wilee unlocks the chain to his bike and the bike and chain fall to the floor. Wilee then picks up the chain and doesn't pick up the bike. But by the time he finishes the call with Manny, the bike is now back to being laid against the tree, when it was on the ground moments earlier. (00:05:00)
Chosen answer: I think that sound is the front wheel giving way. If you look closely, you can see that his front wheel is wobbling a little as he escapes. This may be why he ditches his bike and steals the cop's bike soon after.