Pascal Vasselon, technical director of the Toyota Gazoo Racing Europe team, explained that the issue that temporarily put the TS050 engine into a protection mode hit the the winning #7 car driven by Mike Conway, Kamui Kobayashi and Jose Maria Lopez on one occasion compared with twice for the sister car.
The time loss for Kobayashi when the #7 Toyota encountered the problem at the end of the third hour was minimal because, said Vasselon, he was "faster to react".
#7 Toyota Gazoo Racing Toyota TS050: Mike Conway, Kamui Kobayashi, Jose Maria Lopez
JEP / Motorsport Images
Vasselon explained that there is "a procedure to go through to get away from it, a matter to go through".
Toyota had never experienced the problem with the TS050's twin-turbo V6 before last weekend's Spa 6 Hours, but it did happen to #8 on one occasion during practice for the event. It suggested that the issue was related to "circuit-specific settings".
The #7 Toyota ended up winning by 34s after Buemi had to make a late splash-and-dash fuel stop two laps before the chequered flag, although the positions of the two Toyotas had been frozen at the previous round of pitstops with 40 minutes left on the clock.
Nakajima had been just over a second behind Lopez at this stage after the fourth and final safety car of the race closed up the two Toyotas again.
The turning point of the race in the favour of #7 came in the opening hour when Conway was given slick tyres on a drying track, while Buemi was left on the wet-weather Michelins he had started the race and had to make an extra pitstop.
This allowed Conway to build a lead over the sister car of 50s, which stood at well over a minute in Kobayashi's favour when the safety car was deployed the end of third hour.