A theroy, he fell asleep watching his movie, from just being tired or carbon monoxide, fire started and he did not wake up. Which if that was the case, being a garage there had to be an explosion of some kind at some point (gas cans, the cars), which could have been mistaken for a rev of the truck when waking her up from a deep sleep.
He had to be sleeping (which if it were that late I would have been to), or it was a instant explosion. If it were a normal fire and he was awake he would not have passed in the truck. He would have walked out and attempted to put the fire out/call 911 or drove the truck through a wall or garage door to get out. I would assume he had the keys since he was watching a DVD in the truck.
Wish we had the whole story, to be honest, which I stuggled with here due to the sensitivty of the situation, it seems to me this had to be
1. Faulty heater causing carbon monoxide knocking him out and causing the fire, then a explosion woke her, not a rev.
2. Suicide.
3. Foul play.
I hope it is 1 for all parties involved. While death is never easy to deal with it is worse when death is caused by someone else.
I once experienced carbon monoxide. NOT FUN. It was alomsot 2 years ago, just got the Viper and had the kerosene heater running in the garage, very old heater mind you. I was waxing and changing the plugs. Eventaully I was feeeling sick and started to sweat. But since I was doing what I like I kept working through what I thought was just the start of a flu or something. Eventaully my symptoms gave way to dizziness and I thought to myself it could be carbon monoxide and left the garage. I stood outside in the 20 degree cold for a while just taking deep breaths of air. I started feeling better so I went into the house and grabbed the carbon monoxide alarm and took it to the garage, sure enough it went off. It was a couple days before I felt completly normal.