Filmed at the Kanawaki Golf Club outside Montreal, Quebec, producers had the club house painted yellow for the film from its original white. Members so liked the change that they kept the color following filming.
Before the third round, Eddie tells Francis that he dreamt Francis shot a 72. Franics would eventually go on to shoot 72 in the playoff to defeat Harry Vardon and win the U.S. Open.
In the playoff round, they pan across the 3-player scoreboard very quickly and at the end we see Quimet and Vardon tied at Even. Below their score is Ted Ray at +6. If you go back frame by frame and look at the scores on each hole, we see that Ray is really only at +3 up until this point in the match.
Francis's putt at the end of regulation play speeds up at least twice. It couldn't possibly have traveled that far at the speed it was originally going.