I had one stuck shooter when I had the Ariral battle as well, though it seemed to linger because there were a couple straggling hogs that wandered off. I went leading those hogs back over to the tree house and it disappeared after killing one of them. Usually a save/load cycle gets rid of most event entities, not including ones meant to persist like the hogs.
Viewing post in Voices of the Void 0.8.2 Bug Reports
I didn't see any stray hogs, nothing even shows up on the radar other than the leftover shooter. I will check again whenever I load the game back up today though. If the scrape didn't get rid of the ariral already. The endless event never cropped up again after using the scrape. I played for a few hours and didn't have a problem with saving or sleeping, but it might come back when I re-load