He is reacting out of fear. He hates needles.
Of course -- but it has become an excuse instead of a reason. Most unacceptable behaviors are rooted somewhere in the past in some fear -- rational or otherwise. That is why I am not interested in the background of any horse I buy or train. I do not ask and would not expect to hear the truth if I did get an answer. You have to deal with and have to train what you have at hand. Psychoanalysis is not necessary. To be an effective trainer / owner / handler, you have to deal with what you have and have to teach new, better, more acceptable behaviors to replace the bad ones.
I do not care if a horse goes bonkers over fly spray, a shot, a dewormer tube, a blanket or a blowing plastic sack. For a horse to be a useful partner and a safe 1000# plus animal to handle and be around, they have to yield to your wishes and demands. If you cannot train them out of the bad behaviors that can put other people in jeopardy, then they should be sold or sent to someone that can fix the problem.
I am not trying to be hateful or harsh, but Vets and Farriers should not have to be trainers or risk life and limb trying to handle horses that have bad manners. When I trained for the public, I cannot count horse many horses were brought to me (or I had to go pick up because they would not load) that were sent because the 3rd or 4th Vet or Farrier had driven off. Training a horse is not their responsibility.