Suppose the slot hadn't come forward? Then you would have had people complaining they had been called back to the gate in an hour for no reason.In a situation like this we do the best we can with the information we have available. Another poster has already made the point that ATC was up and running again much quicker than initial reports suggested it would be. When passengers were informed of the delay, slots were not expected to come forward as quickly as they did. With a normal slot delay it is generally ryanair procedure to board up on time and file a ready message and wait for the slot to come forward. However this evening in question was not a normal slot delay. ATC computer systems had failed, hence a ready message would have had no effect. ALL flights were delayed due to the ATC failure, and it was impossible to predict when ATC would be up and running again. As a handling agent we also follow the instructions of the airline...have you considered the fact that the crew may have refused to board the passengers once they were told the ATC system had crashed? Ryanair crews are worked harder than most, and may have wanted the chance of a break! Some of your fellow travellers would have been as annoyed at being kept on board the aircraft as you were that people were allowed to go back to the departure lounge. There are better facilities available in the departure lounge than there are on board a B737, and staff probably felt they were doing the best thing in terms of passenger comfort. Just because you didn't like the decisions made, (which may actually have been made by Ryanair and not Servisair), does not mean you were mishandled.