They would have likely known about the delay, and that they should have a system of telling people about delays.
I remember recently I had an MS to Cairo at 0300-at 0015 they called and said that the flight had been pushed to 0630. This gave me a few more hours of sleep, but eventually the flight took off at 1000, something they had known about but who knows why they did that? All I can say is that airlines have an annoyingly vague way of relaying delays to passengers and yes, we don't expect the airline to be held accountable for unforseen delays, but we DO expect some sort of forewarning. I suggest, krazykat that you write some sort of complaint, and given your premium traveller status they'll grant you some miles.