It happened to me, too
{Warning, spoiler!}
I was playing on some renderman hunt, i just got around building some abondoned houses'n'crap i found some incomplete maze, i took a look in it, nothing to say, i decided to get into the roof to make some kind of map if i need, i got the screenshot of the roof, when i landed, some brother was looking at me with no name, i checked if my F5 is on or off, it was on, i got my hammer and tryed to forget his head off, it disapeared when i got close, i decided to abuse events to point a arrow where the renderman is.
it was teleporting constantly, i cant catch him, nor you.