Have to say I'm struggling with the AvH take on this on this.
You can argue about legal process perhaps, but.....
P1 can't enter flightdeck. Why? Because according to AvH there's no evidence he entered the emergency code ( well
AFAIK there wouldn't be...) or it might due to a mystery defect reported previously.
Then somehow (presumably AvH think due to another fault, coincident with the door remaining locked) the aircraft begins a descent that ends with ground impact....