You explicitly penned away the right to do what you're doing here.
The EU maintains that Ireland gave Apple preferential tax treatment that was not available to others and thus amounts to a subsidy which Apple must now repay. We agreed not to give subsidies under EU treaty.
Ireland maintains that we put in place an attractive tax regime available to all to encourage FDI. This is allowed under EU treaty and law, and in fact is used by all EU nations.
So if the EU are right, we get roughly 13 billion in back taxes from Apple. If the EU are wrong (which I believe they are) then we don't. The reason that this is so heated is that it at the edges (Apple were the only company to take advantage of the rules at the start) and there is a worry that this is an overreach by the EU commission which affects the ability of the government to levy its own taxes, which the the countries making up the EU have agreed is up to the individual countries.