MLeake, I think you have hit the nail on the head. If any of you folks care to do some further reading about mis-conduct of PPD toward open carry folks please go to: PAFOA.ORG
There are numerous stories about PPD doing exactly what you say. Some of the stories actually show video accounts of cops harassing law abiding citizens. Gun owners here in PA are getting sick and tired of cops who do not obey the law. Right now there is a demonstration being planned to high-light this wrongful behavior of the PPD.
From your post #22:
"Open carry is legal in PA, too, so as written the cop should have had no cause to assume a crime was in progress, nor to act as he did.
"There was a thread a while back, though, about a PPD interoffice memo instructing Philly officers to stop and verify status of open carriers, with an underlying intent to discourage OC."
It is not the job of cops to enforce their prejudices (anti-gun) because they feel the need to hold the monopoly on use of force.