Hi Les, There is no treble that we have used that has not opened, this includes Decoy, Owner ST66 and 76, GT Recorders, VMC Tropics etc. The Gamma GT Recorder is most probably one of the best GT hooks and strong as hell but they do open and will be in various situations from pressure from a fisherman with heavy drag with the fish hooked badly to the fish being hooked with the back hook in the mouth front hook in the side or bone and one of the most difficult to believe but a GT hitting the lure while in another fishes mouth which opens up split rings and hooks very easily if the hook has a quick jolt of extra pressure put on it while under the initial pressure.
Part of the fun of GT fishing is that you are going to destroy tackle and have good stories to tell!
Cheers,
Nick