Lead,
Fine and beaut. I understand precisely where you're coming from:
That C is "safer" than E, when analysis only requires E, is a devoutly supported myth, but no matter the sincerity of your devotion to the notion, it is still a myth
That's OK
Lead. It won't wash in the aftermath of a disaster, but I still respect your devotion to numbers. As I alluded to before, no amount of verbage related to concepts such as 'vanishingly small' and the association of a human life to some abstract figure called 5E-9 will save the poor dick who signs off on this.
I hope he's an avid reader, because he'll have plenty of spare time.