Sure, so an accident is often defined as an incident where a person reported any sort of injury. It's a lot harder to get comparable statistics on that. It's easy to make a list of every person who has died in a car, but it's not easy to list every sprained thumb.
The total accident rate nowadays is roughly on the order of one accident per 1M miles driven (there are on the order of 100 accidents per fatal accident), so we could expect the Google car to have its first minor accident soon if it is exactly on par with the average human driver, assuming they have the car drive an average traffic pattern and don't cancel their tests during difficult weather conditions or difficult traffic conditions. In reality they're not going to do that. It would be grossly irresponsible to do that sort of testing before they feel the car is as good as human drivers in virtually all imaginable traffic situations.
Traffic tickets are even harder to compare since it's a human making a judgement call depending on lots of factors.