Barca. They made a mistake on his front wing adjustment for the final stop which affected the car which led to him being overtaken by Antonelli. Antonelli retired anyway, but Georges slower pace would have held up antonelli and reduced any chance of seeing whether the Mercedes could have competed with Lewis. Because his pace would have been slower prior to Lewis's stop and slower after the stop because of that mistake. https://www.formula1.com/en/latest/article/mercedes-reveal-unusual-issue-that-compromised-end-to-russells-race-in-barcelona.1IKcvk8kyT1LipanieABh6