David McHugh, who officiated at Saturday's AIB All-Ireland League Division One semi-final between Garryowen and St Mary's College at Dooradoyle, has offered an explanation for two controversial incidents, the sin-binning of St Mary's second row Steve Jameson and his decision to award Garryowen a penalty try that provoked heated debate.

The Cork official, widely regarded as Ireland's top referee, incurred the wrath of the St Mary's contingent in the immediate aftermath of the game and many neutral observers found these decisions perplexing.

McHugh, who sent off Garryowen prop Kieran Ronan during the match for dangerous use of the boot, explained: "In relation to sending Steve Jameson to the sin bin, it was for taking out Garryowen scrum-half Tom Tierney. "Jameson, who was already in an offside position caught Tierney by the collar and threw him to the ground as the scrum-half was trying to take a quick tap penalty from the correct spot.

"I had earlier spoken to the St Mary's College captain about a couple of off-sides at rucks. The event that preceded the sin-binning involved a line-out in which Shane Leahy was taken out, in my view dangerously, for which a penalty was awarded. That is not a sin-bin offence and in fairness to Steve Jameson, he might have misinterpreted for which offence he received the reprimand."

Jameson's departure with Mary's leading 17-3 proved a pivotal moment in the match as Garryowen took full advantage or returning to equal playing numbers. St Mary's coach Steve Hennessy, who had been critical of McHugh in the immediate aftermath of the game, admitted that he appreciated and agreed with the decision of the official on learning the reason for Jameson's 10-minute sojourn on the sideline.

"I thought that Steve was sin-binned for upending Shane Leahy in the line-out and Jameson claimed as he walked past me that he had done nothing. Now that it has come to light that Steve was penalised for interfering with Tom Tierney then I fully accept Dave McHugh's decision.

"We would not expect Conor (McGuinness) to be prevented from taking a quick free so we can have no complaints."

The source of rancour for the Dublin club was McHugh's decision to award Garryowen a penalty try. The Cork official explained: "I penalised St Mary's prop John Maher for deliberately killing the ball. I thought there was a very clear intention to do so and as it happened one metre from the Mary's line I felt that a penalty try was justified."

Hennessy's view differed: "I thought that it was a harsh decision. Pat Humphreys (Garryowen's hooker), the smallest player on the pitch, tapped the ball to himself, went for the line, but got isolated in the tackle. We had more defenders there than attackers and while a penalty was justified, I thought that awarding a penalty try was extreme.

"Remember this was not a repeated offence, just one incident. But while I would argue about that decision, I have since watched the video of the match and we have no one to blame but ourselves. We made silly mistakes. The last thing I want is for people to think that we blame Dave McHugh for the defeat. We do not. It was down to our own inadequacies."

The IRFU are expected to announce today the suspension incurred by Garryowen prop Kieran Ronan for his sending off in last Saturday's match against St Mary's College.