In the restaurant, a Pepsi clock is shown with the slogan "The Pepsi Generation," but in June of 1963 Pepsi's slogan was "Say Pepsi, Please... For Those Who Think Young." The "(Come Alive!) You're in Pepsi Generation" only began later that year.
In the first scene of the morning of 22 November 1963 a paperboy is throwing a newspaper from his bike. He is wearing a Texas Rangers baseball cap. The Washington Senators did not move to Arlington, Texas and become the Rangers until 1972.
At about the one hour point, Robert Ryan and Burt Lancaster are in a mirror filled room, going over their final approval of the plan. The camera man shooting the scene is clearly reflected in the center mirror panel.
At about 29 minutes in, Burt Lancaster's character says that in May (Oswald) was distributing "Fair Play for Cuba" literature in Dallas. The historical record shows that Oswald distributed leaflets for this organization in New Orleans, not in Dallas.
As President Kennedy is riding through Dallas, each of the conspirators are watching the event on television. Although his arrival was covered by national television, the only television reporters with him were at the back of the motorcade, or at the Dallas Trademart....Hence they could not have witnessed the assassination as it happened.