No one will really know the answer to the question, but there is some indication that this may be true. The best place to look for an answer is right at the dragon's mouth - the Traffic Court rooms in all San Francisco Bay Area courtrooms. Here you will see everyday citizens come in on a daily basis. You will also see how the system treats them - not very fairly. Both the guilty and the innocent check in, but the majority of the time mostly the guilty check out. Another words most people, even if innocent of the charge, are found guilty. This is because the Court's, IMHO, give greater weight to the testimony of the Officer then they do to the testimony of the accused! This is a legal no, no, but it happens on a daily basis.
If you have received a ticket for speeding, red light camera, stop sign, commercial violations or any other traffic violation, you should have a knowledgeable Traffic Attorney on your side!