Bouncing off just one part of that, whether or not he'd a sociopath, etc.
I don't think he is that. I don't believe he killed Cooper on purpose. But there is this, when I insist on intellectual honesty, which I do.
I've rewatched the part of his LE interview, multiple times now, when he is recounting his day to Stoddsrd and he says I went to lunch and...LONG pause.
It IS a long pause. There aren't any other pauses like it in the interview. What was he thinking?
I believe he would have been highly unlikely to pause had he intended to kill Cooper and/or hadn't intended to, but realized before noon that he'd forgotten Cooper, and arranged a lightbulb trip to check.
That moment of checking would have been the very moment he would have known he'd have to account for, convincingly. I can't be convinced RH didn't think it was at least possible, if not absolutely probable, that LE would speak to his lunch time friends.
So why did he hesitate, then omit the lightbulb trip? IMO, it's because his telling of the chronology was the first time he realized Cooper was in the car then, and for all he knew (right?) , was still alive, or at least, might have been, because he had no way of knowing for sure, because he in fact didn't look, didn't check, and worse, wasn't prompted to remember Cooper, even standing there near the car.
That's what I think may have run through his mind in the brief pause, that and just as quickly, better not tell LE about that because it looks bad and they'll use it against me, and I need to get out of here, not give them any reason at all to hold onto that phone which, if they search it , will send me to prison.
So, here's the thing about that pause and how he responded. I find it almost impossible to believe he could have been so deeply in shock that he'd show no emotional response to suddenly realizing he was right there at the car, perhaps could have saved him, but in any case could have prevented his dead son from being alone in the car, abandoned, for hours longer.
What kind of person, realizing that, pauses, then goes on, matter of factly describing the rest of his day, in an effort to save his own arse?
Not a sociopath, necessarily, and not a murderer, necessarily, but for a fact, necessarily, if that's what the pause was about, a man who couldn't possibly have loved his son in any definition of the word I can understand.