Scholarships were increased afterwards, and the situation improved. Aided by freshman eligibility brought on by the Korean War, Notre Dame finished 7-2-1 in 1951 and 1952 while the 1953 squad, Leahy's last, posted a 9-0-1 docket. A controversial 14-14 tie against Iowa denied the Irish another potential national championship. There was some concern about Leahy's health when he collapsed from a pancreatic attack in the locker room during halftime of the 1953 Georgia Tech game. A priest allegedly gave Leahy the last rites of the Catholic Church when it was feared he was dying.
The controversy over the tie with Iowa stemmed from the fact that both of Notre Dame's touchdowns (one late in the first half and the other late in the game) came after a player had faked an injury. In both instances, Notre Dame had used up their allottment of time outs, and under normal circumstances, time would have expired in each half before they could run another play. Faking an injury was a widely-used ploy in football as a means of buying time, but in most cases there was no impact on the outcome of a game. In Notre Dame's case, they used this ruse not once but twice in the same game, and both times they managed to score touchdowns. A new rule was implemented the following year forbidding players from faking injuries, and many saw this as punishment directed at Notre Dame, who were branded as the "Fainting Irish." It tarnished the image of both the school and its coach.
Leahy resigned on January 31, 1954 with two years remaining on his contract. Supposedly he had been ordered to give up coaching by his doctors for the sake of his health, but he later revealed that he left because he felt he was no longer wanted. While at Notre Dame, Leahy had six undefeated seasons, four national championship teams and an unbeaten string of 39 games (37-0-2) in the late 1940s. He also coached four Heisman Trophy winners - Angelo Bertelli (1943); Johnny Lujack (1947); Leon Hart (1949) and John Lattner (1953) - and recruited a fifth, 1956 winner Paul Hornung. His overall record at Notre Dame was 87-11-9.
Like his former coach, Knute Rockne, Leahy believed that games were won in practice and had the reputation for being relentless. It is said that Leahy's teams never had a practice without hitting and that his quarterbacks would catch snaps every practice until their hands bled. His teams were always well conditioned and Leahy was merciless when it came to the toughness of his players.
In addition to his practices, Leahy coached a tough-nosed style of football during the games. Leahy's teams rarely kicked field goals when they were on the goal line because Notre Dame didn't kick field goals. Notre Dame was too tough to kick field goals. This philosophy backfired against Army in 1946, when the Irish drove all the way to the Cadets' 4-yard line and turned the ball over on downs. A field goal might have won the game.
Leahy was succeeded by Terry Brennan, ushering in a downward slide for Notre Dame's football fortunes for the next decade.
In 1949 he wrote a book on the T-formation, "Notre Dame Football T-Formation".
Leahy always referred to his players as his "lads."