Ballymena in the wrong?

It would appear that Ballymena are going to be kicked out of the Irish Cup due to playing a non registered player who in another twist just happened to score the winner in yesterdays game down at Newry,according to the papers he wasnt registered in time for the Irish Cup deadline which I believe was the end of January,so who's at fault then?,is it the club who claim they got the OK from the IFA?,or is it the IFA themselves who told Ballymena that the player was free to play this weekend but failed to inform them that that didn't include the Irish Cup?,either way it's another mess for the IFA to sort out but this seem's to be a trend for the IFA season after season