Red Bull has called for a clarification about how the DRS overtaking system can be used whilst yellow flags are being waved.
The stewards conducted a three-hour investigation after Mark Webber spotted Mercedes’ Michael Schumacher using his ’DRS’ inside a yellow flag zone at Valencia late last Sunday.
Ultimately, the officials let Schumacher keep his first podium for more than 2000 days, Charlie Whiting arguing that "the decisive element" is not whether the DRS flap is open but "whether the driver has slowed or not".
The FIA race director added that there is "no rule" specifically forbidding the use of DRS under yellows.
But Red Bull team boss Christian Horner told Austrian Servus TV: "There was a meeting where it was said that DRS and KERS may not be used under yellow flags.
"For this reason we told Mark not to enable DRS and so I was surprised that Michael did."
Peter Sauber admitted: "From past experience we know that the FIA applies different standards from time to time."
The Hamburger Morgenpost newspaper wondered if the fact it was Schumacher’s first podium of his comeback, and in the presence of his friend and FIA president Jean Todt, that influenced the stewards’ ruling.
Mika Salo, one of the stewards at Valencia, said: "I am not allowed to talk about our decision."
Horner said: "I think it is important for the teams that we clarify the situation for Silverstone."