We are talking about the last point in this case. And, in the official interpretation of the Laws of the Game (p. 102), it is defined thus:
Quote:
“gaining an advantage by being in that position” means playing a ball that rebounds to him off a goalpost or the crossbar having been in an offside position or playing a ball that rebounds to him off an opponent having been in an offside position
The referees obviously decided the Irish player has played the ball, therefore, this was not an offside. And I would say this was a correct decision, given the time it took the ball to pass through the defense line – it was not a quick rebound, the ball stopped there for a second. (But I could not find a close-up video of what exactly the Irish player did with the ball.)