Funniest thing would be this scenario:
The two idiots get into a screaming slapfight again. He stops the van, she stalks off in a huff. He waits around for her to cool down, she doesn’t come back. He goes after her and finds out she tripped somehow. Hole in the ground, rock, doesn’t matter. She tripped and either bashed her head or broke her neck, either way she’s either dead or close to it and he’s the last person to see her. There’s absolutely no evidence showing he did it, but there’s also absolutely no evidence proving he didn’t. Idiot panics and wants to go home. Runs away, panicking, spends too much for a hitch.
Of course in this scenario I fully expect him to an hero, because there’s about a 99% chance he goes to jail for forever.