If I remember correctly, the engineering for the airframe has some built in safeguards - if there is hole punched in (or out of) the airframe, a panel around this size is the maximum that should detach. What happened here is the exact opposite of what occurred in the Aloha Airlines flight (243 if I remember correctly). If that's the case, the airframe responded correctly to the failure, and (albeit there were no fatigue cracks in this airframe) half the cabin didn't peel away. A good outcome none the less.