Brendon Hartley has been held responsible and reprimanded for causing the collision with a GTE Am car that cost his Porsche a likely World Endurance Championship victory at Silverstone.
The 26-year-old was leading by over 40 seconds when he attempted to lap the Gulf Racing Porsche driven by Mike Wainwright around the outside of Farm, the fast left-hand kink that follows the first corner.
At the exit, Wainwright took the usual line and moved to the outside of the track at the same time as Hartley was moving towards him at the exit of the corner.
Hartley, who had much of his car ahead but was still overlapping, hit the side of the GTE car, which launched the Porsche LMP1 onto its side briefly before both cars slid into the gravel trap.
"You are reminded that LMP1 drivers are liable for the way they overtake slower cars such as LMP2 and especially LM GTE cars," said a stewards' statement.
"In this case, the stewards consider that Mr Brendon Hartley is responsible for the lack of caution and didn't watch out before overtaking car #86."
Hartley described the accident, which happened shortly after the two-hour mark, as a shocking moment but did not suffer any injuries despite coming close to rolling at high speed.
"I wanted to get past a GT car on the outside, which is quite normal through there," said Hartley in a statement issued during the race and before the stewards' decision.
"But the driver didn't see me and used all of the road.
"I don't want to blame anyone, it was a shocking moment and a true shame."
Wainwright was also uninjured in the crash.
"I was a passenger, he said. "I didn't even know he was there."
Autosport has produced a standalone special magazine to celebrate our 70th birthday. All current print subscribers will receive a copy for free. To order your copy of the 196-page Autosport 70th Anniversary issue, please go to: autosport.com/autosport70th