I honestly believe that they were fighting on the drive over there and she was pissed he was insistent on going to the party and she didn't want to and/or was mad because she wasn't "invited." I think when he got out of the vehicle and got just past the vehicle, he slipped or fell due to either weather or just being drunk and he was down on his knees or crouched or what have you and she was so drunk and so pissed that she either already had her vehicle in reverse from her attempts to park or she thought she had it in drive, but had it in reverse by error because of drunkenness and after she finished looking at her phone, gunned the car to leave, but it went backward and hit him while he was already somewhat down and trying to get up. My dad hit the gas on his vehicle in reverse by mistake and you would not believe the damage that he did in a short space and span (luckily no people were involved). I don't think she intentionally hit him or killed him. But even in accidents a person who is culpable has some measure of punishment.
I don't believe the conspiracy cover-up theory.
Who knows what kind of animal attacked his arm while he lay dying. I think it was an animal that did the damage to his arm and that was not caused by the vehicle. As for the defensive wound to the front of his hand... He was drunk - he could have hit his hand on anything that night. I've hit my arm on doorknobs as I'm walking or hit the back of my hand on a corner of a table, etc. that left a bruise - and not because I've been drinking, but it can happen.
I believe it will be a hung jury.