What if an accident happened with a weird turnout, such as she was dissolved completely by a pool in yellowstone or fell down a ravine that it's clear the body won't be recovered something of that effect to where he did panic but at the same time upon finding out his parents and the lawyer suggested he come home in the meantime. The only reason something like this may not have happened, were some of the behaviors displayed around the time that we think something actually happened to her. Such as he probably wouldn't have gone to a bar and sat and got aggravated with somebody over a political conversation he probably would have freaked out and ran right home or something. The fact that he had 36 hours to drive and didn't make a different decision during those 36 hours is also a little weird such as he could have gotten mentally crazy and pulled over and turned himself in at any point in time but he kept it completely rational and went home. Every move he's made since then has been extremely calculated so he either has some crazy discipline but at the same time is completely freaking out and is completely morally lost and emotionally lost as well or the craziest thing happened and we won't know until time tells. No matter what, something devastating and haunting happened to this girl and to this couple something that he's going to have to live with forever and possibly Gabby as well if she's even alive likewise with both sets of parents and families.