With regard to the interrogation tape, I think it shows that JRH has a pattern of behavior of only getting upset because he was caught.
When he was first put into cuffs and sat down in the patrol car, what happened? He started acting out, yelling, and hyperventilating. He did that only once then stopped. Minutes later he is trying to strike up a conversation with a police officer about how long she has been on the job (Why? So he can guess if they suspect him?).
Now we go to the interrogation room, where things start getting real to him again - he starts sucking air very loudly, and doing what I hesitate to say is "crying," more like panicking about his situation. Then when the cops show up, he immediately calms down. He remains calm as the cops are questioning him. He's alert, forthright about whatever information he wants to give to the police, aware of his surroundings, articulate and seemingly eager to cooperate. He tells some lies, like that his marriage is happy and healthy.
Then the cops leave JRH in the room with him. It starts to sink in that he's not "free to go." He starts panicking again, this time pacing around the room, breathing loudly, making noises, ect.
The cops eventually come back and eventually tell him that they're going to charge him with child cruelty. Once again he behaves perfectly calmly, but has his defense prepared: he has no history of abuse against children and no history of domestic violence charges. Not once does he vehemently deny killing his kid, or insisting he loved his kid way too much to be cruel to him. It's like he expected the police to charge him with something.
Now we watch him get to talk to his wife. Once again, he's breaking down sobbing, only this time for much longer and in a much more genuine way. He's actually upset now because he knows he's going to go to jail. And his wife? Don't ask me to comment on her. (I did end up commenting later :gaah
To me, all this shows that JRH's main concern is for himself and only himself. His grief only becomes truly real when he's facing jail time and that speaks volumes.
Of course, there will be people who say everyone grieves differently, but one would have to ignore all the testimony in the beginning of the trial to believe that. All of the witnesses at the scene came from various backgrounds, races, and walks of life, and they all agreed on one thing: that people grieve differently but JRH's behavior fell outside the range they would expect from a father who just lost his son. Both civilians and law enforcement testified that they felt JRH's behavior was forced and just from what I've seen, I agree with them.