Sorry to interrupt the chip-shouldered predictable BA bashing - just want to point out this whole public trial by heavily-edited-youtube clip was started by a spotter with a scanner who pretends to be an air traffic controller on some virtual flight sim/ATC network.
There is more to this than the recording suggests. Dublin ATC isn't great. With due respect to the Dublin ATCOs, who have to work within the constraints of a runway and taxiway layout that doesn't help them much in its design.
And this wouldn't have happened at Gatwick or Heathrow, for many reasons. ATC procedures built to take into account the needs of the operators (not just ATC) and high density ops taxi-way design (multiple holding points for departure) being two that spring to mind.
Anyway, sorry, back to the spotter led bashing. Fire away chaps.