I’m not a fan of the theory that she injured him so severely on Sunday, that he succumbed to his injuries on Monday.
Logically, that does make a hell of a lot of sense. An act of abuse goes too far, and a child dies (we see that a lot on here).
What troubles me, is that he’d have to be well enough to walk to the vehicle, and then die at some point over the next few hours.
Then we have TS apparently trying to account for blood in the garage. So we’re talking about violence that not only causes internal injuries, but external ones as well.
That’s why I’m still leaning towards murder to cover up abuse, as opposed to an act of abuse that directly resulted in Gannon’s death (albeit delayed).
It’s incredibly unusual, but I think it fits better with what we know.