Jon, like it or not, this is another example of the gross (and oft illegal) decay of our God-given natural rights. This call could, and should, have been handled better - and I only say that based on what I've read. Correct me if I'm wrong, but I believe even if it was a real gun that no law was broken.
No way to tell was not real until it was handled.
Once a 911 call was received the LEO had the obligation to respond. By the way, there is an excellent article in SWAT this month on "Snitching". When LEO magazines rag on the abuse of police powers every month, that should tell everyone something is wrong with the system.
The can be and is abuse of power, position, etc in every aspect of life not just police work.
Anyway, speaking from experience (LEO / Public Safety), here's a little insight to the physiology of a call:
First, "Nosy-Nancy" who doesn't know the difference between an AR15 and an egg-beater, places a frantic call to 911 about a mad-man with a big scary gun holding a kid in his vehicle.
Dispatch puts it out as a man with a gun possiblly...attemtped robbery...abduction of a child...etc, etc.
By this time, in the cops mind, it's already been confirmed a man has a real gun in the act of doing something that's not 'according to Hoyle'. Now, it's his chance to put down a bad guy. Couple that with mega-doses of adrenelin, lack of experience and lack of training and you have incidences like the one in question. (Look at the old lady in New Orleans).
The N.O. situation was much different with the old lady. I do not agree with what those goons did to her after speaking with her knowing she was not threat.
From what I understand, the caller stated that a man in a super market parking lot was putting a gun together in his vehicle. What would you or any reasonable person suspect?
Tony, if you do have experience as a LEO, wouldn't you agree that it would be good street smarts to approach that situation as a "felony stop"? If not, I hope I never have a back up or partner that would operate that way.
Now, it seems all policies these days are written on the basis of officer safety. That's well and good until it goes so far to violate civil rights for no good reason.
Scene survey and self assessment seem to go out the window a lot of times when someone else tells you what is happening. You take it for granted instead of making up your own mind. I'd bet things would have been different if the cop was walking by and observed this himself. At least, I hope.