Lucky?
Sure, because the FO was well-trained and handled the emergency well.
But...
When maintenance screws up, and they do, on occasion, it's the pilots left holding the bag.
Investigators found that when the windscreen was installed 27 hours before the flight, 84 of the bolts used were 0.026 inches (0.66 mm) too small in
diameter (
British Standards A211-8C vs A211-8D, which are #8-32 vs #10-32 by the
Unified Thread Standard) and the remaining six were A211-7D, which is the correct diameter but 0.1 inches (2.5 mm) too short (0.7 inch vs. 0.8 inch).
[4]:52 The previous windscreen had also been fitted using incorrect bolts, which were replaced by the shift maintenance manager on a like-for-like basis without reference to maintenance documentation, as the plane was due to depart shortly.
[4]:38 The undersized bolts were unable to withstand the
air pressure difference between the cabin and the outside atmosphere during flight.