I don't disagree with anything you have said regarding the severing of the charges. I just don't think that it is cut and dry. Did Judge Staley make the correct ruling? I am not sure. If JRH is found guilty, it will definitely be part of the appeal. The ruling makes me very nervous.
Here's where I personally get hung up. Cooper's death was not instantaneous. When Ross left Cooper in the car, Cooper spent an extended amount of time baking in the car. I am not sure if Cooper's approximate time of death has been released, but JRH had time to realize his "mistake." Up until shortly before Cooper's death, Ross could have returned to his car, retrieved Cooper, and saved him. If we believe what has been reported, JRH spent his morning sexting with 6 different women, one of whom was a minor. JRH's sexting prevented him (at least in part) from recalling that Cooper was still in his car. Given that, the sexting is one, if not the only and main, component of criminal negligence. I believe that the jurors will decide that JRH showed a "reckless disregard" for Cooper's safety when he opted to sext instead of care for and protect Cooper. IMO JRH's behavior both in originally "forgetting" Cooper in the car and then subsequently forgetting him for the rest of the day is likely a direct resulting of his sexting. One of those girls was a minor. Why should that fact be hidden from the court? from the jurors? If the sexting evidence is admissible, why would the charges be severed? Since these were concurrent crimes and it is not out of the realm of possibility that one crime (sexting with the minor) resulted in the other (leaving Cooper in the car and his subsequent death), I don't think that the Judge Staley overreached when she denied the DT's motion to sever the charges.
Wanting a "child free" life is not criminal. However, it becomes criminal if one murders his child in pursuit of that desire. My mind is not made up on whether I believe that JRH wanted a "child free" life. Given how loose some of the parties in this case have been with words, I will wait to see what is revealed and subsequently challenged during the actual trial.
On another note, why does the DT want Juror 20 to remain in the pool? Juror 20 stated that she believes that JRH is guilty, has posted comments about potential sentencing, and reiterated today that she doesn't believe forgetting a child should go unpunished. Can anyone imagine what the DT's strategy is on this juror? Are they hoping that the prosecution uses one of their strikes on her? I cannot even fathom what their motivation is.