Steve, this is not a Court Of Law, its a court of public opinion. Well informed opinion if you are a pilot and know the business.
Yes, we are all familiar with those other superior Courts, where misscarriages of justice happen regularly, and where the guilty often walk away scot free thanks to the efforts of scurrilous lawyers. In a Court Of Law we see the Law applied - and Justice denied much of the time.
The details we know so far (I won't call them FACTS yet, in case you get upset) are pretty hard to explain in any other way than an intentional act (e.g. the repeated locking of the door). And in fact I don't see you questioning the deliberate nature of the act. You seem more interested in stopping speculation on his motive.
We may indeed never know his motive. But I think he lost the right to 'benefit of the doubt' when he locked that cockpit door.
I'm interested to hear your speculation on why he'd do that while sitting watching the aircraft fly into the ground (assuming you think he was really just a passive witness).