Concussion for three days? ?

My bf didn't talk to me for 4 days. I just heard from him and he claimed to have fallen down the steps while moving a dresser and was knocked out and went into a 3 day concussion, and tht he was in the hospital for those three days. My friends say tht he's lying because you won't be hospitalized for knocking yourself unconscious. and tht the hospital wouldnt have kept him there for tht long if he wasn't fataly ill. ( they think he's lying) r they right?