Here's the problem. The average law-abiding citizen no longer sees a cop as a friend or ally. That's almost always based on personal experience, mine included. So cops are no longer given any benefit of the doubt in situations like this one.
It's up to the police to change this perception.
I have actually had a cop pull me over in the middle of the night for no reason whatsoever, and ask if they could look in my car, then detain me for 45 minutes when I asked, "What is your probable cause?"
Outside Lewistown PA, about 15 years ago I had a cop literally scream in my face for five minutes because I pulled into the passing lane to allow him to merge onto the freeway.
When my vehicle was broken into and my tapedeck, tape and computer equipment were stolen, I was advised by a helpful policeman that filing a police report would just be a waste of his time, and instead a better course of action would be to "pray for sickle cell anemia."
I was pulled over for a field sobriety test that held my son and me up for a half hour. I asked if I was driving erratically or something and was told that I was driving in a college town at 2:15 AM, and that was reasonable suspicion enough. When I asked the cop for his badge number, he actually pulled out one of his business cards and threw it in my face.
People are predisposed to believe the worst of cops -- on a conservative forum no less -- because they're constantly doing this kind of crap. Thankfully, I've never had to rely on a cop in a life threatening situation.