Rotor,
I have no suggestions on what he did or why he did it as my Crystal Ball is in for routine maintenance.
All I can do is consider what happened.
He hit a Crane in Cloud. Everything after that is pretty much ordinary supposition beyond the information noted by the AAIB Report.
There is an old Greek Saying that fits your question.
"I should smell my hand and know what he was thinking?"
Barnes did not record his thoughts for consideration by the rest of us.