You never mentioned what type of gun breaking you did prior to your hunting trip. Hopefully the dog was gradually expossed to the sound of a shotgun, not just pots and pans, and cap guns. If so, there wust be another reason the dog went shy. Was the dog gun broke to the sound of just one gun, or multiple guns? Where your hunting buddies on that day the usuall group, or were there different players involved? Was everyone on their best behavior? There are so any variables to concider.

As stated earlier, I agree that pots and pans won't help at this point. Train only by yourself, and keep the dog in lots of birds. Buy them if you have to. Get the dog so excited that he doesn't notice the sound of the cap gun from 100 yards away. Fire it while he is occupied with the bird, either chasing it as it flys, or aggressively trailing, not while pointing. Always act like nothing happened after the shot.

Also, after you have the dog cured keep the number of guns shooting over it down until the dog is well matured.

I have always gun broke my dogs independent of the bird field. I start while they are eating, move on to walks and exercise sessions, and eventually move on to the skeet field. I want my dogs to be completely gun broke, not associating gunshots with reward. they will learn that later by themselves.

I also limit who I hunt a new dog with until the dogs second season, and sometimes late in the second season if I feel it's necessary. I don't need too many gun shots, and too many people confussing my dog.