There is nothing inherently wrong with a neighborhood watch guy or anyone else following a person on a public street, possibly even “chasing” after them to keep up. That would not justify the followee beating the daylights out of his follower. Indeed, a follower who was in contact with police and providing the police information.
Seems awfully unlikely Zimmerman “attacked” Martin. Zimmerman sustained multiple injuries before firing.
I’m active in my neighborhood though not a neighborhood watch. I’ve called the police to report suspicious people. The police are always supportive. If I called the police and the guy started beating the tar out of me, I’d damn well think I had been suspicious for a good reason.
There certainly is not. Especially considering the dispatcher directed Zimmerman to "Just let me know if this guy does anything else."