While Det. Scarfe lies dying on the pavement in the alley. Misty is shown kneeling over his body crying, "No, No" several times. During this shot, in the far background you can see the blurry orange lights of 2 NYPD cruisers pulling in from both left and right. However, following some dramatic shots of the scene from above and roughly a full 20-25 seconds later, the 2 cruisers are clearly shown arriving as if for the first time.
No matter that Luke is Unbreakable and very strong, he can not stop a car by putting himself in front of it because he is not heavy enough to stop it in place. He would be tossed off, and Claire and Scarfe would be dead.
When Scarfe and Claire are in the back of the van, she tells Luke to take the right turn, the movement in the rear windows show the van turning left, but the outside shot shows the van turning right.
Scarfe's wound leaves a large amount of blood on the washing machine, yet there are only a few spots on the floor at the barber shop. If he was bleeding that much he would have left a trail of blood all the way from where he was shot, which would have been easily spotted by the police.