Or a self driving bus with children could get confused by a weird sticker and jump of a bridge, hit a giant truck stopped in the middle of the road.

We are speculating here, we need numbers to see if this self driving cars are better, how do we get this numbers though? Is it fair for the citizens of a city to be forced to be part of this tests? Are we sure the correct number of incidents are reported from this tests? are the tests good enough for real world (are they testing in all conditions are avoid some streets or some weather to keep the numbers looking good)

They're testing in California. I.e. flat-ish, wide roads, relatively nice weather. Sure, it's ideal for baby steps, but passing this off as "look at our safety record, therefore it's safe anywhere" is disingenuous at the very least.