That was the version of the story I heard as well, Now, for some reason, that little fact has seemed to have disappeared from the public record.
Consistent with the dishonest reporting on this issue, most quotations end right here. Omitting Zimmerman's immediate response.
Zimmerman: Ok
Which at least implies that he was agreeing and stopped following.
The entire remainder of the call has nothing at all that would lead one to believe Z was continuing to follow M. It's all about how Z will meet up with the cops, etc.
I think it's reasonable to think that if he were still following, he would have made some comment indicating it.
I think it’s also obvious from the transcript he was already out of the car when the dispatcher suggested he not follow Martin. Yet the media reporting has universally suggested she told him not to get out of his car.