Lol since when does the dog get to decide what correction is fair or unfair. I would say drop the prong and go to the dominant dog collar on leerburg or an E Collar.
I would also train just about everything positively and go out of my way to minimize opportunities for misbehavior through management.
Some dogs respond well to a come to Jesus moment and some keep coming at you until they are dead.
There is a dog I know of that was worked on 2-3 lines in an attempt to achieve compliance as he would turn on his handler if pushed. He was hung numerous times and everytime he woke up from never never land he would again attack his handler. In the end he was kenneled and used for breeding.
Personally I would have tried a more positive approach first but thats just me..
Such shy animals are in all circumstances an encumbrance to their owner, who must be ashamed of such a dog, and a disgrace to their race. Under no circumstances whatever must they be used for breeding, however noble and striking they may appear.