You cant one day be perfectly healthy and the next day loose it, it's just doesn't happen. This man has either had an ongoing mental illness (psychotic illness) like Bipolar slowly developing away, or he has had something else happen medically. I doubt quite highly that he would be able to get away with BP in aviation. People who have serious mental illnesses do not know that anything they are doing is out of the ordinary. So their flighty ideas would stand out and be picked up by family, friends and his work profession.
I feel so sorry for this man and hope that he recovers soon. Well done to the F/O. He did everything right I believe.
