Probability/Statistics are fraught with peril!
As noted....167 hours and 4,000 hours on something that was supposed to be safe to some astronomically figure to the 10 to the umpteenth power as I recall.
Add in the fact it happened to exactly one Operator and that really begs the imagination!
The view must be great out there where you lurk.....bit wobbly when the wind blows though I bet!