Lt Col Slade sternly warns Charlie not to refer to his .45 pistol as a "gun", but rather to call it a "weapon" or "piece" in accordance with military custom. Moments later just after Charlie refers to it as a weapon, Slade then refers to the pistol as a gun (which was most likely an intentional contradiction of what he had just told Charlie).
In the hotel scene following the Thanksgiving family scene, Frank is assembling his .45. When Charlie calls the .45 a "gun," Frank corrects him, saying it is a "piece" or a "weapon," but "never a 'gun'". A few moment later, Frank tells Charlie "a Colonel never gives up his gun!"
When discussing travel plans, one of boys says he thought they were going to Stowe (rather than Sugarbush). Phillip Seymour Hoffman's characters corrects him, saying, "Sugarbush is Stowe." The two are not the same, nor connected. Sugarbush Resort is in Warren, VT, while Stowe Mountain Resort is 40 miles away in Stowe, VT.
In the scene where Frank crosses the street and falls in the grass, Charlie, helps him to stand up again. At first, Charlie doesn't have the walking stick, but when Frank stands up, Charlie inexplicably has the walking stick in his hands.
In the scene where Slade directs Charlie to get his dress blues from his closet, there is no Silver Star ribbon on the jacket. In all the later scenes with the dress blues there is a Silver Star ribbon.
During the driving scene, a left turn is made and a the rear of the car begins to drift. Application of counter steer (to the right) can be observed from the external shot, and then on the next camera angle from the inside of the vehicle, Al Pacino's character is seen recovering the steering wheel from the left.
In the scene where Slade is threatening to commit suicide, he has tears coming out of his left eye and not his right. When the camera breaks away and then returns, the tears are flowing down his right cheek and not his left.
When the colonel and Charlie get out of the cab at the airport to catch their flight bound for New York, they are clearly at Newark airport less than 10 miles from the Holland Tunnel into New York City.
The car is being driven next to the Brooklyn Bridge with the World Trade Centers in the background. With the east river on the left, they are looking north while the WTC's are south of the Brooklyn Bridge.
Several times during the movie, Slade handles what is supposed to be his U.S. Army issue M1911A1 .45 caliber pistol. But the pistol has a bright blue finish, white highlighted sights, and wood grips with a medallion. These features identify it as a civilian copy of the M1911A1.
Four unit citation emblems are mounted in one row over the right pocket of Slade's Army dress uniform. In actual practice, the emblems would be arranged with only three in the row, with the fourth being placed just above and centered on the first three.
While Slade is explaining to Charlie the proper way to perform the military salute, he says the right hand should be positioned "at the hairline." Doing this would result in a ridiculous-looking salute. The proper position for the hand is adjacent to or just above the right eye. Additionally, in a proper salute the arm is raised and lowered in a fluid motion. The right arm is never "snapped" to or from the right eye as the salute is rendered. Finally, the outside of right hand is always canted towards the individual receiving the salute, in accordance with Army custom. Slade does not cant his hand properly when he salutes Charlie.
Frank and Charles order drinks before Frank does the tango. The waiter never arrives with the drinks. Even though Frank and Charles had changed tables, they hadn't moved so far that the waiter would not have been able to find them.