You quote the UK Act
"Where in any proceedings under this Act a question arises —
(i) whether the adequate level of protection specified in subsection (1) of this section is ensured by a country or territory outside the European Economic Area to which personal data are to be transferred, and
(ii) a Community finding has been made in relation to transfers of the kind in question,
— the question shall be determined in accordance with that finding”.
In other words, when a question arises about the adequacy of protection, the question shall be determined in accordance with "a Community finding (that) has been made in relation to transfers of the kind in question".
My understanding is that the "Safe Harbour" designation represents exactly such a "Community finding" - in other words, the ODPC's hands are tied - Safe Harbour specifies that whatever data protection laws apply in the Safe Harbour location are deemed "adequate". If the NSA access in the US doesn't breach US DP laws (as if!) then there isn't a breach for the ODPC to investigate.
That's exactly what Safe Harbour was designed to do, and the ODPC in Ireland doesn't have the option of ignoring Safe Harbour that was granted by the EU.