A vehicle driven by Google software has been determined to be responsible for a motor vehicle collision in Mountain View, California (archived). Google's car was derping along at 2 miles per hour when it struck a bus travelling at 15 miles per hour. Google attempted to justify itself with the excuse that it thought the cumbersome bus would yield when Google's smaller vehicle was travelling the speed of a particularly slow pedestrian. Google's car sustained damage in the incident.
From their stats of 17 crashes in 1.3 million miles, it looks like they have an accident rate about 10X the national average. Fortunately no fatalities yet.
And seriously. Google seems to drive like old people about to get their license pulled.