Cant say i know what happened or why it happened, but can say that it couldn't have been something easy to deal with if the pilot didn't inform the probably concerned pax. I prefere an informative note over the PA to be made immediately and discuss this with my F/O before T.O. As you do, and although i am not aware of the reason for this G.A, would say that the crew a)forgot about the passengers, b)was unaware of the problem so could not really make anything over a PA which would have been really helpful to the pax and c) were too busy complaining at the head attendant for not securing.
Colleagues, do you not all agree that the securing of the cabin should be carried out pretty early as possible? Maybe a lack of communication before landing?