Walpole???? Oo? Oh, yer mean Trubshaw?
Oh dear!
But they were test pilots, which places them, and the airframes that they might overstress in a quite different category. Quite apart from the fact that had they overstressed the airframe they'd be responsible enough to admit it...
Airline pilots who commit aerobatics in their airliners are in the same box as child molesters as far as I am concerned.