I have seen this many times, especially in the C "terminal", 1 counter flashing "EU", the others "All other passports".
The "EU guy" checking every passenger if s/he is EU and the guys in "all other passports" just wave through until someone stops and says, s/he needs a stamp.
Even worse in the A "terminal" , there is an Irish/UK Queue on the right and "other passports" and EU on the left. Irish/UK guy checks everyone for entitlement (have you bus pass ready if you come from the UK) and in the EU queue just waives people through.
Last week coming from London they demanded Passports/Driver License from Irish people (comon travel area my behind), when people refused and said, they only need some sort of picture ID for London there was mega stress.
Sometimes I think the NIB on the Airport is run by the DAA....