People seem to misunderstand HOW Shane died.
I think there is probably a major misconception of how this happened. People hear that they were "muddin", so they figure that they got stuck, gunned the engine, and died within minutes from an intense fog of exhaust.....WRONG!
It likely happened much slower than this. They probably got stuck, and were just too drunk and tired to worry about getting out in that moment. They probably decided to sleep it off and solve their problem during daylight when they weren't so drunk. Unfortunately, they probably got cold and had to start the truck again to get the heater going. This means they probably died after all three of them were sound asleep.
This was a very sad tragedy that likely wouldn't have turned out so tragically if they had gotten stuck during the daytime.