Ulster coach, Neil Doak, said no player could be given a licence to give away a needless penalty and get a yellow card into the bargain.
The Ulster boss was responding to a question following lock Dan Tuohy’s sin-binning which resulted in an eventual concession of 10 points and probably took the chance of a rare Dublin victory away from the side.
Leinster had been playing slow ball from their ruck for most of the first half and Tuohy succumbed to temptation a minute from the end of a first half dominated by the visitors with the scoreline level at 6-6.
Tuohy needlessly dived in off his feet to take out scrum half Isaac Boss and following his sin-binning, Madigan converted from in front of the posts.
Down to 14 men and under the cosh early in the second half, Tuohy’s team mates were caught napping when Madigan - who scored 19 points in total - cheekily took a quick tap penalty and got over for a try.
His conversion made it 16-6 and Ulster never recovered.
Asked if he could give Tuohy a bit of licence with the situation of slow ball, Doak replied: “No! You have to play the line. Simple as that!”
Tuohy, along with Roger Wilson, had been impressive in a first half the visitors dominated, both prominent in ball carrying and keeping Ulster going forwards.
Doak accepted Tuohy may have done well up until that point but the penalty giveaway was not acceptable.
“Yes he did do well to that stage, but until the whistle goes for half-time and full time, you have got to be on the money especially against top teams.
“It is a lack of concentration. It was Dan this week, it was something else last week and something else the week before.
“We have got to get better and we have to get better at it away from home.
“Discipline is hurting us.”
In spite of the loss, Doak said there were several reasons why the side were not performing to the standard of the past couple of seasons.
“We have had 11 or 12 first team players not available to us for a vast majority of the season.
“A couple of yellow cards and a red on the road have cost us. We could still have won those games if we had taken our opportunities.
“A couple of referee and TMO decisions have unfortunately come back to haunt us and a couple of missed kicks at goals.
“In the last couple of weeks we could have won games had we not missed a few kicks at goal.
“Those are the small margins at the top end of professional sport, it is the way it goes sometimes.
“We also have to take our chances and that is the biggest frustration for me at the moment in not taking them.”
Doak added: “It is not due to a lack of hard work from the players.
“They are training well during the week and it is just when we get to game time that they have to start to finish those chances.”