Installation flaw: Someone didn't bolt the hatch in properly when building the aircraft (which was rolled out two months ago).
Design flaw: The hatch, since it's not a door, should be designed so that it can never fit out the opening and the more the pressure builds, the tighter it gets.
In this case, it sounds like it was both a design flaw and an installation flaw.
Well, the ejected section of plane showed up in someone’s backyard. Which should make it easier to determine what actually happened and institute the proper fix. Darn lucky that the only loss to passengers was one shirt blown out the hole. Good reminder to keep your seat belt on whenever you can.
My guess is no bolts were installed when the miss hap occurred. From what I’ve seen, the door plug uses some existing fuselage structure to secure the plug. After a few take offs and landing, the panel gave way..