Zimmerman sues.... about everyone actually.

When did the dispatcher tell him to leave the kid alone?

The dispatcher asked if Zimmerman was following, and he answered “yes”.
The dispatcher then said “Ok, you don’t need to do that”.

I fail to see where that is “leave him alone” or “don’t follow him”.

The specific thing they said was “you don’t need to do that.”
Not “stop doing that.” So although they said he didn’t need to do it, they did not tell him specifically to stop doing it. Thus, he didn’t ignore anyone.