How can they possibly have up to 9 sigma? 6 sigma is a failure rate about 1 in 10 billion, whereas 9 sigma would be 1 in 10^19 or so! That's oddly similar to the number of grains of sand on the earth![1]
The math will happily pop out absurd numbers. Remember that all stats carry assumptions with them, such as "this is a Gaussian process from negative to positive infinity" and "everything is absolutely perfectly independent" and other things that break down if your push them hard enough. What that is telling you is just how hard you're pushing the math rather than the real odds. I'm not 1 in 10^19 sure of anything.
[1] http://www.hawaii.edu/suremath/jsand.html