you’d be surprised how common it is to “slip and fall” directly onto some random object that’s is by pure fluke, lined up perfectly with your ring piece.
Since in this case the unfortunate man was unable to retrieve the object himself it has to be assumed that it went up his arse in its entirety.
At 17cm long I can only assume that it was well lubricated and not dry. Presumably he must have done something like accidentally knock over a bottle of olive oil, which happened to be nearby, before the unexpected anal intrusion.
So unlucky. And to think I sometimes complain “what’s the chances of that happening?” when events appear to conspire against me.