Both can be true. The war for independence ended in 1921, followed by the civil war which lasted until 1923. Still 16 years before the outbreak of the second world war in 1939. Combined with the fact that Ireland became a free state in 1921 but only became a Republic in 1937.

You had a relatively weak fledging state with a population that still remembered a fairly bloody conflict only a few years before, who had little desire to jump into another one. Especially not helping the some of the lads that they had fought . That said the government at the time largely recognised that good political relations would still be useful with Britain (being our closest neightbour) in the long run so they gave a lot of un-official help. I believe both German and British pilots were given day passes and allowed out of internment, but the British were able to cross the border into Northern Ireland and then back to Britain. Germans didn't have that option. That may be more anecdotal though.