it seems that the Irish government would actually get the extra money and suffer little for its part in the scheme
So, if the government was the victim because some of its members decided to abuse power in order to get personal compensation (be it money or just public opinion), why would the government itself be penalized? It's true that the government is made by elected members of the people in a democracy, but these people did NOT represent the government's best interests with the deal, as the deal did not do justice to the government by breaking its law.
It might even have benefited the country overall, with new money getting in through other revenue from Apple keeping business there, but that is just a political illusion of benefit to the government - it is more of a treat to the elected political party, who managed to gain popularity to the eyes of the community by committing public taxes for it.
Deals like this can be done, as long as they are made under the guise of a solid investment and they do not break any trade policies without lawmakers consent, which does not appear to be the case.