PA Sport - Wed, 17 Feb 14:32:00 2010
An independent disciplinary panel found the offence, which forced Palisson from the field with a dead leg, had been reckless rather than deliberate.
The Munster hooker, who has the right to appeal, was fortunate only to concede a penalty after his wild swing connected with Palisson after the Brive winger had picked up a loose ball.
Referee Wayne Barnes consulted his touch judge Stuart Terheege, who believed the challenge to be a "shoulder charge" and so Flannery escaped a potential red card.
But replays showed the severity of an incident which could have caused serious injury to Palisson.
Rory Best of Ulster is the likely choice to replace Flannery at hooker after recovering from neck surgery in time for the Six Nations.
But losing Flannery will be a bitter blow to Ireland as they seek to pick up the pieces of their shattered Grand Slam defence.
England at Twickenham on Saturday week is their next assignment before finishing the tournament against Wales and Scotland.