The Stewards reviewed the video evidence, team radio and heard from the driver of car 5 (Sebastian Vettel), the driver of car 55 (Carlos Sainz) and team representatives.
Car 5 had just finished a push lap and was on an in lap, travelling quite slowly into and around turn 1, on the racing line. The driver conceded that he had passed car 55 between turns 7 and 8 but assumed it had pitted after.
However, car 55 was actually commencing a push lap and closed on car 5 rapidly along the pit straight and into turn 1. During evidence, the driver of car 55 stated that he felt the driver of car 5 was completely unaware of his approach.
This was confirmed by the driver of car 5 who stated he was unable to see car 55 in his mirrors and that his team had not informed him of its approach, by radio. The latter was confirmed by the team representative.
It is the belief of the Stewards that notwithstanding the absence of a radio call, the driver of car 5, being aware of the issue of rear vision with his mirrors, should not have been so slow and on the racing line, during a slowdown lap in Qualification.
Having reviewed all alleged impeding incidents since the beginning of 2016, the penalty of a drop of 3 grid positions is consistent with all other similar incidents.