I have no idea obviously what happened in Tim Bosma's last moments, but could it be possible he was shot or otherwise harmed with a box cutter perhaps, and the perpetrators(s) thought he was unconscious or dead, but he wasn't? Perhaps when one of them left the vehicle to go to the waiting Yukon, Tim made a dash for his life and then the driver of his truck, who I believe it is alleged to have been DM, drove over him to finish him off? I just imagine Tim would have fought back with everything in him to escape from such monsters, IMO. That would explain how his blood was found underneath the truck, IMO, as some of you have surmised here.
ALL MOO.