When Jim is ironing his suit and Elston comes in to talk to him, the iron is placed with the handle facing away from the suit. In the next shot, the handle is toward the suit.
The thugs confront Jim in the pouring rain. The front passenger window of the 1973 Chrysler Imperial is wide open, yet the person sitting there does not get wet.
The Septa bus had a single panel door. No Philadelphia buses used this arrangement. They all had 2 double panel, double hinge doors at the front and at center.
Swimmers did not use goggles in swim meets (not in Philly anyway) in 1974. They were used in practice. Googles in meets started later. Also swimmers did not use the style of start (grabbing the block and throwing your arms forward) in 1974. This also started much much later. I was a swimmer in Philly in the late 60's till about 1977.
The Brothers Johnson's "Strawberry Letter 23" was released in September 1977.
A 1982 Oldsmobile Delta 88 appears in several scenes.
The O'Jays' "I Love Music" was released in February 1975.
The shots of the Philadelphia skyline at the beginning of the movie reveal many buildings that did not exist in 1974.
When Sue drives away after meeting Jim at the diner, the camera is reflected in the window of her car, over Terrence Howard's shoulder.
When the PDR team goes to Main Line Academy for their first meet, their bus crosses the Benjamin Franklin Bridge, going into New Jersey. Both Philadelphia and the Main Line Academy are in Pennsylvania.
During the final butterfly event, the digital display shows the order in which the teams finished. A moment later the announcer switches the order of the second and third place teams.