McKinney took the helm of the Lakers for the 1979-80 NBA season, but only 19 games into the season, he suffered a near fatal head injury after falling while bicycling. His assistant, Paul Westhead, was named as the team's interim head coach while McKinney tended to recovering from his accident. However, the length of the recovery and lingering doubts about the complete return of McKinney's mental faculties, combined with the team's level of success under Westhead, ultimately meant that McKinney would never get the chance to return to the job. After the Lakers' advance to that year's NBA Finals, McKinney was fired in favor of Westhead and the team went on to win the 1980 NBA Championship.
McKinney went on to win the NBA Coach of the Year Award the next season at Indiana, leading the Pacers to the playoffs for the first time since the ABA-NBA merger brought the team from the American Basketball Association to the NBA in the summer of 1976. Over the next three seasons, however, the team's performance regressed, and McKinney was fired after the Pacers posted the league's worst record in the 1983-84 season. He was soon hired as the head coach the Kansas City Kings, but resigned from the position on November 18, 1984 after the team started with a 1-8 record in the 1984-85 season.
McKinney also was a longtime coach at Saint Joseph's University where he was also an excellent basketball player and member of the track team. He is a member of the Saint Joseph's and the Big 5 Halls of Fame. He was also named the ECAC Coach of the Year for his 1973-74 season at Saint Joseph's when his Hawks, predicted to have a poor year after graduating Mike Bantom to the NBA and Pat McFarland to the ABA, had a stellar season again winning their conference and earning another trip the NCAA Tournament.
In 2005, McKinney co-authored a book about his experiences at Saint Joseph's, and donates ten percent of the proceeds from that publication to Saint Joseph's.