Zimmerman was exempted the second he pursued Martin. There was no imminent threat.
Using your logic, a rapist who pursues a woman and then shoots her when she fights back, shouldn't be arrested.
Compare apples to apples or dont compare at all.
Now...before I go on....I dont have nearly enough information to determine if the shooting was justified or not....I am not on either side of the fence ion this...and no one should be.
That being said...back to apples to apples...
What WOULD have been a proper analogy....and using YOUR quote....
"Using your logic, a person who pursues someone they beleive raped someone then shoots that person when that person fights back, shouldn't be arrested"
But for some reason you have opted to cvompare Zimmerman to a rapist.
That is immature and not the American way.