Though I am not a doctor (but I think I did play one on TV - not sure - amnesia!) I am sure that contrary to portrayals in any number of movie plots or soap operas, temporary amnesia is very, very, rare.
Physical damage to the brain will cause memory loss, some medications and alcohol blackouts will limit short term memory, but otherwise, it is a great story device, but likely bullshit.
This guy is just nucking futs.