The FIA has described Valtteri Bottas' start at the Austrian Grand Prix as a "fortuitous judgement call" after he began moving almost in sync with the red lights going out – promting complains that he jumped the start.
Both Sebastian Vettel and Daniel Ricciardo questioned Bottas' start and remained certain after the race that it was a jump start, and although the race stewards investigated the matter, they didn't punish the Mercedes driver.
The FIA later confirmed that although Bottas moved when the lights were on, it was within a small tolerance that is permitted in the rules, and he didn't move outside of that tolerance until two-tenths (0.201s) after the lights had extinguished.
"The jump start system judges whether a car has moved a pre-set (very small) distance between the point at which the last red light comes on and the point at which the lights go out," said an FIA spokesperson.
"We have found that need to allow for some very small movement, as drivers sometimes need to make clutch adjustments in preparation for the start.
"This system, which is dependent on the official timing provided by Formula 1, has been in operation for some 20 years and has proved extremely reliable in that time."
The FIA admitted Bottas' start was probably a 'lucky guess' in that he anticipated when they would go out, rather than reacting to them, but that is still a legal start.
"In today's instance, Valtteri Bottas did not exceed this (very small) limit before the start was given.
"Simply put: he made an exceptionally accurate and fortuitous judgement call, anticipating the moment the lights went out with great precision.
"Any movement prior to the moment the lights went out was within the tolerances allowed."