McLaren says the pit stop mess that ruined Jenson Button's Malaysian Grand Prix was caused by human error.
Button was on course for at least fifth place when he prematurely pulled away from his third pit stop. His car's right-front wheel had not been properly attached and he had to stop in the pitlane and wait for his mechanics to pull him back.
Button spent nearly 1m45s in the pits during the incident and fell to 14th place. He recovered to 12th before retiring due to a severe tire vibration.
Team boss Martin Whitmarsh said the pit stop traffic light system had been triggered early and given Button a signal to go.
"For about 120 milliseconds, he had a green light, so with lightning-speed reaction – just as he's paid to do – he pulled away," Whitmarsh said. "Those lights are controlled by a whole number of circumstances, like micro-switches and buttons that are around the car and a button was pressed and then released for about 120 milliseconds.
"These people are trying to do sub-two-second stops. There's a lot going on in that time and a lot of pressure on people. Human error resulted in a green light.
"It's one of those occasions when you wish your driver wasn't so quick off the mark..."
Asked if McLaren may revise its procedures in light of the incident, Whitmarsh felt major changes would not be necessary.
"There are fail-safes in there," he said. "I think there are other things we can do, but at the end of the day this wasn't a system failure."