The corner cases are extremely important and are only "rare" relative to the overall number of people driving. When you have 100MM cars (not a researched number) on the road, that one in a million chance happens 100 times every day!

I've had this same argument at work a few times and although I fully admit the idea of a self driving car may be safer in the future, you will not be seeing me in the first few generations of these cars. I generally don't consider myself a luddite, but this is one area where I will prefer manual control for quite a while.