What Causes Bleeding Without Any Cuts After Accident?

This isn't the normal question, but here goes. My friend was just in a car wreck a few hours ago. He was walking down a street when he saw a girl was about to get hit by a car, so he pushed her out of the way and got hit himself. He has only minor cuts, and suffered from temporary shock and amnesia.. But the weird thing is that there were 5 liters of blood on the scene, and it tested out to be his.. But he had not lost any blood. Please, is there any explanation?