 Hackett also officiated at the 1988 Olympic Football Tournament, handling the semi-final between Brazil and West Germany, which Brazil won on penalties following a 1–1 scoreline after extra time.He refereed the 1990–91 league encounter between Manchester United and Arsenal at Old Trafford, a match notorious for the 21-man brawl breaking out just after the hour mark.The melee resulted in Arsenal being docked two points and Manchester United one by The Football Association, upon a three-hour consultation with Hackett and his match officials.