Okay, the other day (version .47) my friend and I encountered this player.

We engaged him in conversation. The guy responded, but only my friend could hear the guy talk. I heard nothing from the guy, but heard my friend talk "double", i.e. heard him on both TS and VOIP when he held down his 'caps lock' key.

I was close, less than 5 meters.

No other people on TS and friend was quiet, no other noise in the room or anything, would normally have been able to hear him perfectly well.

Like five-ten minutes later, we run into another guy that we can both hear perfectly well.