Remember there are TWO main classes of errors:
Type 1 errors (Rejecting the null
hypothesis when it is ultimately found to be true)

Type 2 errors (failing to reject the
null hypothesis which is ultimately found to be false)

......
When the events are of extremely low probability and yet have disastrous
consequences, we probably need to re-think the way we assess the risk;

.......
-especially when we do not have the data needed for a proper risk assessment
(i.e. it has never had the event happen)