I think this actually has the opposite implication from the one you seem to be trying to draw. If different teams finding the same bugs was common, then someon

I think this actually has the opposite implication from the one you seem to be trying to draw. If different teams finding the same bugs was common, then someone else probably would have found this one sometime in the last 14 years and reported it to Cisco such that it was actually closed. Therefore, finding overlapping bugs is rare -> NSA should stockpile bugs. (We probably should have a separate agency in charge of attempting to make things more secure, perhaps by finding and reporting bugs like this)