This is one of the strangest and most disturbing FA stories I've read on FT. OP, thanks for your thorough, consistent narrative.

Like others replying to the thread, I'm baffled as to how the FA thought he could get away with the blatant lie that police were waiting for you at the end of the jetway. As was pointed out above, that's not something a lone FA can initiate.

If that had happened to me, I'd have immediately spoken with a UA rep at the airport so that the FA could be identified. As it is, if your written narrative was sufficiently detailed, it should still be easy for them to piece together who it was. Maybe when he's confronted about his behavior, he'll come clean.