Jerry, I thought I had heard Cyril Wecht say the tendon was severed, I guess I was wrong on that. Regarding bending of the wrist, he did not bend it till well after the shot so I do not think it was involuntary. It looks like he did it to allow the hat to fit between himself and the door. My point was not about the fingers and thumb, it was about the wrist position changing.
To say he could still move his wrist because it did not need bone graphs misses the point. Just having a bullet pass through the wrist would make it painful and difficult to bend the wrist. Also I think because the wrist bones are mounted on the radius it would be painful to articulate the wrist.
These are interesting points to discuss but I try not to reach absolute conclusions about subjects like this. There just isn't enough data.