I'm surprised that one unfortunate police encounter has been in the news so long. A police officer wrongfully arrested a professor who wrongfully called him a racist. The fact is that innocent people do get arrested all the time, and police are called racist all the time. I think that this case is attracting a lot of attention because of Professor Gates' social status. If this happened to an auto mechanic, we wouldn't be hearing about it.
A couple thoughts:
1. It generally doesn't serve one's interests to call a police officer a racist or otherwise insult him. If he's not racist, he might get offended. If he is in fact a racist, then you aren't telling him anything that he doesn't already know.
2. Police officers should control their own emotions when dealing with emotional people.
Both the police and the public have to meet each other halfway to get along in the streets.