I've had a couple of strange, bad incidents with cops and then some that were normal interactions.
My worst one happened when I lived out of town in the mountains. The drive home was hilly, so difficult to maintain a constant speed. I drove it relatively conservatively going a little over the speed limit down the hills and a little under up the hills to minimize using excess gas. A cop pulled me over and asked me all the questions, and I answered. He felt a little brusk, but not an issue until he handed me the warning to sign and saw my hand shaking when I signed my name. It wasn't a big deal, but he started saying, "Should I call search and rescue? We can't have you driving all crazy over the road", and he was swinging his arms around. I looked down and not at him and kept repeating, "no", shaking my head. After a while he stopped.
I was scared because all I could think is, "I'm alone on a rural road with an insane person who has a gun". I went into that freeze, understated mode. I think he was a bully and saw that I was actually intimidated when my hand shook a little, and then had fun with it. IDK. The incident doesn't make much sense to me and that's the best I could come up with. Someone once suggested that maybe he thought I was on drugs, but that would be quite a stretch. I was able to sign - my hand wasn't shaking that much. I was also only going 5-10 miles above the speed limit on the downhill.
Other cops have been just a bit rude and stringent. When I lived in MN there was an ice storm where there was zero traction quickly, and when I hit my breaks at a stoplight, I was only going 10 mph, but had zero traction and hit the bumper of the car in front of me. He gave me a citation which seemed a bit harsh. It was a depressing day. I was going over to see my cat during a divorce.
There was one more incident when my car was totaled during a left turn by someone gunning a very red light. The cop was extremely rude to me and asked if I was drinking, so I said feel free to give me the test. I was confused because I think I had a mild concussion, but he was treating me like I was confused before the accident. He put the entire blame on me, and treated me like a wayward drunk. Yes, I have a doctorate and am a high level professional, but once again, I was vulnerable. In this instance not just mildly because I was alone in a city with no one to call, had totaled my car, and was suffering mild brain damage. Oh, don't do that in front of a cop.
I think in these instances I gave off a slightly vulnerable vibe emotionally and they HATE that.