Martin Saunders of Chiltern Archery used to run an indoor league around '96 or '97 which I shot in.
It was handicap based, with 2 archers shooting a vegas against each other, highest adjusted score to win the match. It was good because the league mixed recurve and compound archers.
Anyway, one night one of the compound archers next to me wasn't shooting as well as he thought he could/should. He was a big guy (6'3" ish) and shot a 60lb bow with big heavy, all carbon arrows. His bow was so fast, all you really heard was the shot, you couldn't see the arrow at all.
Well, on one shot, there was a bang and I just caught something flying behind him. I assumed he'd just thrown his release aid down in disgust.
It was actually his arrow, that he'd missed with, that hit the back concrete wall and came back about as fast as he'd shot it.
How it never hit anyone (especially him or me) was a mystery - the place was really quite busy.
Scary
Simon