From what I recall of the Google Car crash - from the basic details I know...
The car had stopped at the side of the road, it was a traffic lane but there was an obstruction (sandbags around a drain), it indicated to move into the next lane and when there was a gap in the next lane of traffic (with a bus approaching), it moved into the lane to go around the obstruction as the computer decided the bus would yield. Apparently the 'passenger'/operator of the Google Car expected the same so didn't over-ride the movement.
So it appears to me - what happened in this case was the autonomous vehicle had been programmed to be 'more human' in driving... thereby contravening a road-rule like many people do all the time without consequence. But, of course, it was still at fault - just like any human driver would have been.
However I do wonder if speed had anything to do with it - apparently the AV was moving at 2mph (my understanding is that is initial pulling-out from stop speed and would have been used to go around the obstruction) where as the bus was at 15mph. I do wonder if the bus driver had noticed the AV but assumed it was going to be moving quicker than it actually did, therefore didn't think they needed to slow (or slow further) in order to yield (not that they legally had to) - course they may just not have noticed the AV was starting a maneuver in any case.
