Too little info to say if it was illegal or not. If she's cuffed him, she has the right to perform a "cursory search" of his person for her own safety for weapons or disposable evidence (drugs). A bag or vehicle would probably not fly. The bag maybe, if she thought you were a courier. In most states, private citizens have a similar right to search for weapons if they've lawfully executed a citizen's arrest, which is why private security can search your person if they arrest you for shoplifting... all under the pretext that the person making the arrest, if it's lawful, has a right to take measures to secure their safety. Now, the parameters for a lawful arrest are a lot looser for a sworn peace officer, so unless there is proof of some sort of discrimination or habitual behavior from this officer, I doubt there'd be much recourse. Unless you know Johnny Cochrane or something. But if the OP feels like he was treated unfairly, he should've gotten a badge # (I prefer to read the badge, not ask for it) and filed a complaint with the dept.

Cops are scared too. They don't like losing control of a situation, so any kind of attitude or resistance seldom works in anyone's favor. They particularly hate it if you answer questions with questions. That's a great way to get on their crabby side.