At the US Olympic Trials in 1972, both Hart and Rey Robinson repeated the world record, running the 100 m in 9.9 seconds, and were favored to win the race at the Olympic Games. But in Munich, they were both eliminated in the 100 m race because their coach, Stan Wright, unknowingly using an outdated Olympic schedule to determine the starting time of their quarterfinal heat, failed to deliver them to the track on time. This failure due to disorganization created much controversy. Hart also ran the anchoring leg in the American 4 x 100 m relay team, which won a gold medal and equalled the United States' own world record of 38.19.
Hart continued to run and in 1989 set the Masters world record in the 100 m that lasted for 14 years.