Make sure your nocks fit your string properly and are a good, snugfit in the shaft. If they're too tight on the string and too loose inside the shaft, that can make the nock hang up on the string and pull out of the arrow on the shot.

I saw a guy do something like that with a brand new Hoyt one day. Whisker biskit set pretty far back. Low brace height. Vanes halfway inside the biskit at brace. He drew, but the nock pulled right out and left the arrow hanging by the vanes inside the biskit. He only had the nock left on the string and didn't notice it as he was fully concentrating on his sights. As we were yelling "LET DOWN" he triggered the release and we all ducked for cover. Bye Bye brand new Hoyt.[&:]