When Reg is closing the door of the truck on the body he has just loaded in, it's fingers get severed. There is no blood flow which would only be the case if he was dead. The same with his hand when Wes and James discover his body in the truck - there is no bruising or blood flow. For the wound to behave this way it would have to have occurred post mortem. For the van driver to then "wake up" when his body is about to be processed is impossible.