You can't blame the officer for badly misjudging a situation, firing shots inapporpriately, firing and hitting the supposed victim, firing without looking for verification that his/her (incorrect) judgment is proper? All because of the breed of the dog, I presume. I wonder if you'd react similarly to improper police shootings in urban neighborhoods.
It also can get tragically out of hand.
Live on the edge, die on the edge.
IMHO the officer reacted as any reasonable person would have.
The results were nearly tragic.
I believe such conduct of wrestling dogs and mock dog attacks in public is highly inappropriate, no matter where it is conducted. Do it at home in your yard of you have to.