Factual error: In the coffee shop when Roy Hobbs is having coffee, there is a Coca-Cola sign in the window featuring the "fishtail" logo used between roughly 1957 and 1961, not the time period portrayed in the movie.
Factual error: During their transatlantic boat trip, on their way to Athens, the American athletes are having fun naming various foods from back home that they already miss. One of them claims he misses chocolate chip cookies. Oops. That particular cookie didn't exist until Ruth Wakefield invented it in 1930.
Factual error: When Rob Lowe first arrives in Oxford he is driving down a street taking in the sights. Most of the sights he views are actually scattered throughout the town and not on any one street. This is especially true for Radcliffe Camera (part of the Bodlean Library) as it is in a cobblestone courtyard completely surrounded by buildings and cannot be viewed from any street.