Gibb finished the 1966 race in three hours, twenty-one minutes and forty seconds, ahead of two-thirds of the runners. Another woman, Kathrine Switzer, also completed the 1967 race having registered officially in line with the rules. Although the Boston Marathon rule book made no mention of gender, Semple claimed her race registration was a result of an "oversight" in the entry screening process. Semple tried to stop Switzer by repeatedly assaulting her as she ran. Switzer wrote in her memoir "A big man, a huge man, with bared teeth was set to pounce, and before I could react he grabbed my shoulder and flung me back, screaming, 'Get the hell out of my race and give me those numbers!'" Switzer's boyfriend Tom Miller managed to shove Semple aside after Semple had knocked Switzer's slightly-built 51 year old coach to the ground when he attempted to protect Switzer; both Miller and Switzer's coach were competing in the race alongside Switzer. Semple complained in a 1968 interview about Miller's success in stopping Semple's physical assaults saying "That guy's a hammer thrower, for cripes' sake!" Photographs of Semple attempting to rip Switzer's number off were widespread in the media. A consequence of Switzer's completion of the 1967 Boston Marathon as an officially registered runner in line with the rules then in force was that the AAU changed its rules to bar women from competing in races against men. Later in life, Semple reversed his position on women competing in the marathon. According to Marja Bakker (a later organizer of the race), "Once the rule was adjusted and women were allowed in the race, Jock was one of their staunchest supporters. He was very progressive." Semple later publicly reconciled with Switzer. In 1981, he published an autobiography, "Just Call Me Jock". He was inducted into the RRCA American Long Distance Running Hall of Fame in 1985. Semple died of cancer of the liver and pancreas in March 1988 in Peabody, Massachusetts. He and Kathrine Switzer had become friends and she would visit him at the hospital where he was being treated for his cancer. The Jock Semple Award given by the Boston Athletic Association is named in his honor.