Ghost in the Machine

So.... what do you do when you hear someone telling about this amazing haunting they witnessed/experienced and you know for a fact it didn't occur?  I've seen someone, I'll call him Lou, going around con to con telling people about this extreme haunting he experienced.  He's very specific about the dates and place the haunting occurred.  He's come up with a name that supposedly everyone called him when "word got out" about the haunting.  He's shopping a book deal.   But the thing is, I lived in the same house as him when this supposedly occurred.  We were in college together.  None of the stuff he said happened really happened.  And I don't feel I can call him out on this because he's MonsterMan.