The fact that she went to talk to him speaks volumes for me. It would be easy to argue this both ways, and I certainly feel that she made a few mistakes during this procedure.
1) One of the best things I've ever heard an officer say was that "Everyone knows who wear are, because of our uniforms. We don't know who ANYONE is though." I think the "was treated like a common criminal" saying gets thrown around a lot more than it should. She didn't rough him up like a common criminal, she put him in cuffs until she could figure things out. What he said about shouting from the roof tops about his permit is true, but at the same time, everyone acts as innocent as possible around the police.
2) If I were charged with the task of critiquing her performance, I would have told her that she should never leave someone in an unknown area like she did. She could have taken him outside at least and put him in her car as well to talk to him. It might not have been less embarrassing for him, but it would have been safer.
I don't like having spotlights and flashlights pointed in my face and car when I get pulled over, or having more than one officer arrive either. At the same time though, I know who they are, but they don't know the first thing about me; other than that I'm driving a beat to shit Honda Accord around in Aurora. It might make me feel embarrassed, but it doesn't mean they are treating me like a common criminal.
If it wasn't for her coming to talk to him and trying to explain her actions to him, then I'd probably have a tone closer to the article, but in this case, this is an event that doesn't really upset me at all.
That's my take. If you'd like to check my credentials, see my avatar.