Could be he planned to join the Taliban all along, and the “bravado” when he first got there was just an act.
I could be wrong, but it sure sounds like he was trying too hard with the Taliban mask idea.
My thoughts too. I have heard the stories (for years) that he was a deserter, or worse. Then, last week I saw his father send some creepy messages to the muslim world, from the White House. The whole family needs to be watched for the rest of their lives. They are not to be trusted.