I know this may sound like a selfish answer, but given the over-reaction that is likely to occur, I would probably not report something like this just because of the possibility of extensive delays and/or interrogation of passengers by buffoons trying to get the big catch.
Before the current madness, I probably would tell the F/A. Now...I don't think I would
(Obviously, if I find a piece of a gun or a ticking package, I wouldn't ignore it.)