I have been informed by the Irish Aviation Authority that the traffic situation referenced involved the Garda helicopter being tasked to an operation in North Dublin and this coincided with the arrival of some transatlantic flights to Dublin Airport. The helicopter was integrated with these arrivals in order to get to the operational area as expeditiously as possible.
A flow of transatlantic flights normally occur around this time of night and the Garda helicopter can occasionally be tasked to various parts of Dublin and surrounding areas. There are no restrictions to Garda helicopter operations.