Despite a bonus-point win over England at Twickenham, the performance was "poor" and "rudderless" according to former head coach Eddie O'Sullivan.
Tries from James Lowe, Hugo Keenan, Jack Conan and Finlay Bealham meant the visitors collected maximum points and trail France by two points going into the final round of the Six Nations championship when they host Scotland in Dublin.
It also proved to be Ireland's biggest-ever win at Twickenham.
England played for 78 minutes with a numerical disadvantage after lock Charlie Ewels was red carded, but while the visitors never trailed, it was disjointed for large parts and the game was in the melting pot at 15-all with a quarter of an hour remaining before Ireland finished with a flourish.
Having conceded 16 turnovers and 15 penalties, some which came against a dominant England scrum, O’Sullivan was far from impressed with what he saw.
"I’m not drinking the Kool-Aid on this one. This was a really poor performance," he said. "We didn’t put England away until the 73rd minute (Conan’s try). We had 14 men for most of the game. I thought we were pretty rudderless for most of the game.
"We pulled away in the end, England were out on their feet, we put together a nice passage of play that broke England and it was all over.
"Three points with 10 minutes to go was shocking.
"Our scrum was a mess, our discipline was awful, our handling errors was off the charts, but we still came away with a bonus-point win. England just ran out of gas.
"No-one is going to convince me that if England had 15 men that we would have won playing like that."
Full-back Hugo Keenan admitted it was far from a vintage display, but that the result was all that mattered, and while O’Sullivan acknowledged the feat in leaving the English capital with the bragging rights, it leaves plenty of food for thought for Farrell and his coaching team.
"We can celebrate the won and the four points, winning on the road at Twickenham, that’s great, but that is not a great performance.
"We can’t expect teams to play with 14 men every week. I’m happy with the win and bonus point, but let’s not get too carried away."