The sniper here was me, and I've certainly never seen anything like this before/after. If it's a bug, is should be reasonably recreatable.
Pretty sure map was Cataract...30yds or so on my side of one of the side flags, sniping at target very close to me, with kestral starting on my Citadel side, and behind me after the snipe cast time finished. I just saw the arrow go *pew* in the wrong direction, and that was that. Maybe it tried to track it's way back around but got caught on the map confines. Certainly odd, and would love to hear if anyone else encounters this as well.