Usually nicks are from wire. Perhaps you had your rig get tangled with another? The other possibility is the fish swam forward after hitting your rig, got the line tangled in the main line ahead of the flasher or the other wire rig before tripping the release. I caught a steelhead on Erie Sunday that showed itself by jumping behind the boat. The problem was it swam ahead and stayed ahead. We knew we had a fish on but no way of telling which rod. Three minutes later the outside board moves back.