I think they had three collapses over the last 15 years and none
were due to
mis-rigging.

And how do you know? Our mechanics said the same thing, but it struck
me as a cover-your-ass sort of defense.

And it is checked every 50 hours and also they hold an stc for
putting a window in so it can be inspected through the nose baggage
area each flight.

They've had the window in for 15 years? The problem only came to
light in the past few years. Our mechanics also put in a window.