One metre may cost Coulthard the title

The McLaren-Mercedes pilot was on his way back on to the track after his first pitstop, talking on the radio to the team, when he prematurely lifted his finger off the speed-limiter just fractions of a second before crossing the white line denoting the end of the pitlane.

Coulthard was slapped with a 10-second stop-go penalty for being just 3 mph over the speed limit and the extra trip to the pits destroyed his race, his chances of victory and, perhaps ultimately, a crucial chance of getting back in the world title fight.

"I can't know how close I could have been to Michael because he was backing off towards the end," said Coulthard. "The fact is the penalty for speeding cost me points. I was just a bit too keen with the button. It has cost me dearly."

The McLaren ace's title rival Michael Schumacher went on to win the French race, meaning Coulthard slips 31 points behind the German with seven races and 70 points still up for grabs as he heads to his home race at Silverstone in a fortnight's time.

"I am very disappointed," said Coulthard, "but you have to push in every area and the pitlane is no different than pushing on the edge of a corner. It is just that the pit limit in the past is not something I have had a problem with. I must have been just a metre too early this time.

"I switched the button off too early and wasn't aware of doing anything different. It was quite an intense moment because I was trying to get information from the team as to where Michael was and the other cars. I was 3mph over the limit. As hard as it was, those are the rules and that is the way it is."

Coulthard learned of his penalty from the team over the radio, but decided to keep pushing in spite of the delay. By the end of the race, the 30-year-old was bearing down on the Ferrari of Rubens Barrichello, but was unable to get by and had to settle for fourth.

"I was very surprised because I didn't think I was that close to it," he revealed. "I knew I had a penalty, at first I didn't know what for. Then the team explained it to me. I wasn't gutted because you never know what can happen during the rest of the race. I knew I had to keep pushing."