What a great site! I appreciate all of the quality minds on here and how we all can bounce theories around. Butler and others make some very valid points. I'm by no means ready to declare case closed, I do think the car theory is at least possible and does match up in some key areas.
For devils advocate purposes my take on some of the questions raised about the car accident theory: If IR was fishing it would be very easy to fool him. He wouldn't hear any noise whatsoever while near a moving stream and if Deorr was bundled up quickly he could be told he's sleeping if he asked where he was. I don't know how well dogs work and not to be too grim but any signs of a low speed accident would probably be pretty easy to clean up. If there was blood on the ground you could shovel up the whole area and throw the dirt in the stream, no one would be able to notice if you just shuffled the dirt around once you were finished. The truck could be cleaned with any rag or paper towels and the evidence burned. Take the remains carefully bundled up and bury them. Go get a car wash, I'll have the deluxe please. Spend about 20-30 mins hauling around and splashing in mud puddles suddenly the truck doesn't look like it was cleaned. Check everything 2x call the cops.
As to the blood found on the truck, I am not an expert in those areas. I know luminol shows blood but who knows how much was spotted and if they were able to verify whether it was human or not. Also I'm not sure finding tiny amounts of blood even if it was human is enough to make arrests, having a confession, body, or witness would probably be needed.
Ok everyone poke away let me know what I missed.