Formula1 website: "The FIA also outlined a number of other options available to the Michelin teams, including running more slowly in Turn 13, running new tyres and incurring a penalty, or repeatedly changing tyres, subject to valid safety reasons. With those options deemed unacceptable by Michelin and their teams, there followed the bizarre spectacle of 14 cars peeling into the Indianapolis pit lane to retire at the end of the formation lap." The crybaby teams deemed those options unacceptable.
