In BA’s defense, they still had a couple of spare engines.
And given that the cause of the failure was unknown, that they didn't know for certain that the other engine on the same side may have experienced damage due to the failure, let alone the jet body itself or flight control surfaces may have suffered some sort of damage, and there is always the possibility that the unknown situation that caused the first failure would eventually manifest itself in the other engines, and let's not forget the fact that the jet didn't have enough fuel to get to LHR and had to land in Ireland, and (worst of all), given the fact the decision to continue was based upon the potential cost to lodge the passengers while another jet was found, in my opinion, I'd say BA made some very poor decisions. They were very lucky that all that happened was a short landing,
But that's just me.