In a Formula 1 race, the chequered flag was waved so violently that the black and white patches got mixed up. Who was waving the flag, when and where?
So this seems a little too easy, but I think the answer is:
Winnie Harlow, 10 June 2018, Canadian Grand Prix in Montreal, Quebec, Canada
The columns of the flag are encoded with Baudot-Murray ITA2 code, and read "TWO MORE LAPS". The Canadian Grand Prix in 2018 was terminated two laps early when the race officials lost count of the number of laps.