Vettel penalized, loses Mexico podium
Having been held up by Ricciardo's teammate Max Verstappen after the Dutchman straightlined Turn 1 and remained ahead, Vettel blocked the fast-approaching Aussie aggressively at Turn 4 on the penultimate lap of the race.
The pair nearly made contact arriving at the corner but Vettel would hold on to what was then fourth position, leading Ricciardo by 3.5s at the checkered flag and then inheriting third place when Verstappen was assessed a swift post-race penalty.
However, his podium remained provisional as the stewards investigated his defensive driving, with both Red Bull's Helmut Marko and Ricciardo himself saying Vettel had violated the very rule against moving under braking that had been recently implemented in response to Verstappen's tactics.
Following a meeting with the parties involved, the stewards gave Vettel a 10-second penalty and dropped him to fifth place for changing direction under braking.
The penalty means Ricciardo moves up to third and Verstappen to fourth, the Australian securing third in the championship.
Vettel was also awarded two penalty points.
Stewards' statement
The stewards paid particular attention to the Race Directors Notes from the US Grand Prix (v2) and from this event (point 18).
Notwithstanding the F1 Commission directive to "let the drivers race" we note the concern that has been expressed about maneuvers involving a change of direction under braking as expressed at the Drivers Briefing at the US Grand Prix and in the Race Director's Notes from the US Grand Prix and this event.
The telemetry and video evidence shows that the driver of Car 5 did change direction under braking.
Article 27.5 and the Race Director's Notes have essentially three criteria that determine a breach
1) Driving in a manner potentially dangerous
2) An abnormal change of direction
3) Another driver having to take evasive action
The video footage, including the close circuit footage, the broadcast vision, both drivers' on board cameras plus the telemetry show that there was an abnormal change of direction by Car 5 and this was considered to be potentially dangerous in view of the proximity of the wheels of each car.
The video evidence clearly shows that Car 3 had to take evasive action as a result. Accordingly as all three criteria have been met, the driver of Car 5 is guilty of a breach of Article 27.5