It was perhaps an unnecessarily polarizing example, but it was the first and only thing that came to mind regarding "move" as pertaining to a lawful order without digging up the name of the rather obscure case that recently got a verdict (wherein it was determined that the officer had no authority to tell the citizen to move, that it was indeed an abuse of authority, and paired with 120+ other abuse of power complaints against that officer, resulted in his termination).
No, they're not generally law officers, however, they may redirect your call to an actual law officer or police dispatcher. I do not know whether George Zimmerman was talking to a civilian 911 rep or a police officer, but either way, the 911 agent did not offer any lawful orders, the most authoritative statement given to Zimmerman was "We don't need you to do that."
Having interfaced with law enforcement at local and federal levels as part of employment, I happen to know that particular phrase literally has no meaning, except "please don't sue us if you do that, because we aren't liable, and need it on the record that we did NOT tell you to do whatever it is that you're about to do."
It's not a statement of encouragement or discouragement. That said though, if you consider the outcry that he "deliberately disobeyed a police officer", it's clear that many do not understand the concept very clearly (or they were blinded by the rest of it and went in to full witch hunt mode, which may or may not have been warranted).