A mistake from Nico Hulkenberg pushed Fernando Alonso's McLaren over the top of the Sauber of Charles Leclerc. Alonso's car bounced off the Halo device mounted above and around Leclerc's head. The device was made mandatory for 2018 despite much controversy and opposition from some drivers and a significant number of fans. Halo was introduced after years of research into cockpit protection by the sport's governing body, the FIA.
After the race, Rosberg replied to a tweet fom the official F1 account showing the tyre marks on top of Leclerc's Halo with the message: "We can end the HALO discussion now.