I would have done the same, because you invited me to hunt there and asked that I not shoot this one buck. Enough said.
When I invite people out to hunt with me, I normally tell them they are free to shoot whatever they want. The only rule I have is, if you shoot a buck, it must be mounted.
You have a very special relationship with this one buck and I can understand asking people not to pull the string on it, wanting to finish the job yourself. I think it is very acceptable that you feel this way and ask this of your friend. I also believe that you have a very good friend to not have dropped the hammer on him, I know I have a few buddies that would have stabbed me in the back. Good luck and I am hoping like a big dog you get your second chance.