False memory syndrome, there was an epidemic of it in the eighties and ninties where therapists were getting people to suddenly remember all sorts of abuse, satanic abuse, murders committed by their parents etc which were eventually proved wrong.
The idea that something could be so upsetting that you forget it until years later is ridiculous, if it were true nobody would have remembered the holocaust, current victims of war and all its crimes would be suffering mass amnesia but the opposite is true. When something traumatic happens, you can't forget, the brain evolved to remember the worst.
I think it was Derren Brown that did a show where he had people tell him all sorts of stuff under hypnosis, all patently untrue and impossible (past lives, war etc), probably sourced from 'memories' in the unconscious from books they had read, what they had been exposed to and perhaps directed under hypnosis. Recovered memories as they were wrongly called have been long discredited.
It's awful that his family has to suffer his reputation being destroyed like that on top of having him missing.