A physical and tactical collapse which nearly cost them victory over Ireland on Saturday left France with more questions than answers.
"We ran out of petrol," said captain Fabien Pelous when he was asked to explain how a team, leading 43-3 after scoring six tries, conceded four tries and 28 points in 12 minutes.
In a frenetic final quarter France just survived an Irish backlash to win 43-31.
"We cracked up physically," said team manager Jo Maso while coach Bernard Laporte was, for once, short of words.
"Maybe we worked too hard in training all week? It's difficult to quantify," he said, acknowledging he could not recall such a collapse since he became national coach in 1999.
"I thought I was watching a film," he added.
The Stade de France crowd quickly forgot the brilliant performance of the first 50 minutes which left the team on course for a record win and their widest margin against Ireland.
Once again, Laporte had become "Mad Bernie" and he responded with an attack upon the fickle French supporters.
"We should only allow the volunteers and the amateurs in the stands. Regarding the beautiful people who get free tickets I would send them on to the pitch. Their case would be resolved very quickly," he said.
During the first hour the French made amends for the defeat at Murrayfield which shattered their grand slams hopes at their first outing the previous weekend.
The recalls of Olivier Magne and Raphael Ibanez paid off. Commitment and hunger were back. A crisp defence put the feared Irish backline under pressure and punished their errors.
The tide turned when Laporte launched a wave of replacements.
Off went Ibanez and Magne followed by the halfbacks, Jean-Baptiste Elissalde and Frederic Michalak, loosehead prop Olivier Milloud and flanker Yannick Nyanga.
Suddenly, the French pack began to fall apart and the whole team looked disorganised.
All the weaknesses reappeared, poor field kicking, lack of power and stamina and no natural leader emerging to change tactics.
Challenged by Ireland coach Eddie O'Sullivan, who stated that his team "played all the rugby out there", Laporte's defiant answer was: "Who won the game?"
"Defeating Ireland is no mean thing. The main thing was to win. It's our first match at home this season and we said we wanted to stay unbeaten at home until the 2007 World Cup which will be played in France. We are still on course," Maso said.
France will play their next two games at home against Italy and England on March 12.