I am an aircraft maintenance engineer and that is one of the most bizarre things i have seen looking at the photos.
Bloody lucky considering it is near the wing root leading edge. Depressurisation was the least of their problems.
Damn lucky they were not over the Pacific and could land nearby. Handling characteristics would have been affected.
Looks like a material failure. Maybe a poor sheet metal repair job from the way it peals backs from the rivet line.
If they were low to the ground they could have been hit by a missile that did not explode. That is way of the radar just thinking laterally, as it is very very unique.
