I don't think there is any merit in the argument that he's insane and not responsible for his own actions. He's completely responsible. All the evidence so far demonstrates he understood it was wrong and it was premeditated.
His autism doesn't impair him to the level he can't understand this. The only other disorder I suspect he might have is a dissociative disorder or maladaptive daydreaming, and it's not at the level where it could be argued he can't control it. This shit about dimensions merging and him RPing as his imaginary friends is a fantasy and an act to get attention online. Up to a point in his life he tried hard to pass as normal. In the video he made claiming he was trolling and his original persona was an act, he almost got it right. I think what he couldn't get right was what wore him down to the point he gave up trying and descended into weird shit, because trying hard was too much effort and wasn't giving him the results he wanted. Add to that the enabling he found online when he started indulging his autogynephilia.
People are going to watch him anyway and putting in effort doesn't stop that, so he stopped putting any effort in, and to an extent it worked because his deluded tranny fantasist persona wasn't entertaining or funny.
If anything what's happened shows that the disturbing sex pest beneath all the facades that was evident way back when he encountered Megan has been there all the time. Once he went through puberty and his libido emerged, he stopped developing in any emotional or mental sense. In that recording that was leaked he sounds the most lucid he's sounded in public for a long time, and apart from a few delusional bits about 'mother and daughter' and deities telling him stuff, it all makes sense and he doesn't even use that fucking stupid falsetto tranny voice.
I don't really buy the argument that it was his parents' fault either. All parents fuck up somewhere, and everyone goes through a phase of resenting their parents for the mistakes that were made. Usually, people mature out of it and accept that their parents could only do what they thought was best at the time. People of Barb's generation are from a different time and thought differently to people now, with a lot of shame and stigma attached to things that probably don't matter to younger generations. Cole has a right to be upset over his mother's concealing of his father's identity, but on the other hand Cole's kind of an asshole in how he's dealt with it and women of that generation are notorious for keeping stuff to themselves about kids they had out of wedlock and were forced to give up for adoption, or miscarriages, or other shit,