Visible crew/equipment: When Father Cave gets up to give his speech and he turns to Father Gallagher, you can see the boom mike move in the top left corner. (00:15:15)
Continuity mistake: Ted and Dougal are sitting in the fourth row from the back for the journey. But when Ted presses the emergency button and after the credits, three completely different men are sitting in their seats. Everyone has been given seat numbers so they should not be sitting there.
Factual error: When Dougal and Ted enter the cockpit, the pilot points out the gauges for 'engines 1, 2 and 3'. They are in a Boeing 737 (the internal layout is that of a 737, not a BAE 146), which only has two engines.
Chosen answer: It's characteristic of someone putting on a fake Irish accent.