Vettel escaped punishment from the stewards during the Russian Grand Prix a fortnight ago after almost colliding with Lewis Hamilton.
The German overtook his title rival while Mercedes called their driver into the pits.
But when Hamilton tried to instantly regain his position at turn two, Vettel supposedly moved twice in a breaking zone – sparking outrage from the Brit.
Hamilton soon overtook Vettel before going on to win the race, courtesy of team-mate Valtteri Bottas giving up his place at the front of the field.
And now Whiting has revealed if Vettel does that manoeuvre again his World Championship hopes will likely be over as he was unhappy with the stewards decision.
“The rule about two moves is traditionally about making a move one way and then making a second move the other way,” said Whiting.
“I think everyone felt that that was what was generally understood by the rule, but I must say that when I first saw the incident in the race in Russia I thought the same: he [Vettel] has moved twice when I saw it from Lewis’ onboard.
“But when you look at it from track cameras and a forward shot when they are coming towards you, it is much less clear: that it looks like one move with a hesitation.
“It doesn’t look like two distinct moves, which is why the stewards did not feel that they could justify a penalty.”
Whiting believes Vettel was lucky to escape punishment in Sochi for his defence of Hamilton.
But the F1 chief has warned that he has briefed race stewards to be more astute when spotting the illegal manoeuvre.
“What I did clarify to them is that if a driver does two moves in the same direction, that is the same as doing one in either direction,” Whiting added.
“So if Seb had gone once, looked and then gone again very, very clearly I think that would be equally bad as making a move in either direction.”
Since the Russian Grand Prix, Hamilton has extended his lead over Vettel to 67 points by winning in Japan.