Mahoo my point was that if the door is closed correctly, then the master warning annunciator light for for the cargo door goes out, and then it is ALMOST impossible for that cargo door to open.
What I had heard happened was that it wasn't closed correctly, which is backed up by Raytheon not having suddenly issued SB's to check the door, or the mechanism that secures the door. If it wasn't closed correctly then they should have had the cargo door light on the master warning panel illuminating the entire time. The only other possible scenario is that both bulbs had blown for the cargo door annunciator, or the annunciator itself was lose (as they often are).
This whole thing could quite easily have been the result of some last minute bags being loaded, or something along those lines.
As far as a door opening on take off not being a big deal. I really do beg to differ. What if it had been the front air stair door and it had then smashed into the left engine? A cargo door or cabin door opening during take off and in flight is a very serious even in most aircraft.
I do agree that it was well handled in the end though, and don't for a minute doubt Eagles training or crew standards. I'm just saying that this incident could most likely have been avoided.