Giving fake ID at reception is asking for trouble. Always submit correct ID., as in case of raid etc, you have not done anything illegal. As far as the phone call goes, next time he calls, ask him to join you (or your friend, as the case may be). If your friend is scared, he can get blackmailed.Another questions that begs to be asked is how are the other experienced mongers handling this? Do you give your real IDs at the reception? Or do you use fake Ids?
In this case, I suspect, someone from the reception playing a prank on him. Ask him to relax.