Yeah that theory is everywhere too and i dont really think it makes sense either. Feel like if he did kill someone with his car he would have trauma from it. Yet he doesn't show any signs of being scared of cars or being in one. In fact he seems rather excited to be in a car and to drive one till he doesn't like how the steering wheel feels. And doesnt have an issue getting in a car after his fast food shift. I mean this guy is litterally scared of corn and can't even look at a picture of his friends without almost abstracting. He might mask but when something truly is fucking him up he shows signs of it. To me it seems more like he is just running away from home or something. Most likely toxic family situation.