In the scene where a hungover Bendix sits up in his hotel room bed, the camera pans to show an almost full bottle of liquor. The next shot, from a different angle, shows the same bottle almost empty.
On December 6, 1941, Hannify claims that Dwight D. Eisenhower is a lieutenant colonel and a member of the General Staff in Washington, D.C.. However, he was promoted to brigadier general on October 3, 1941 and was not appointed to the General Staff until after the attack on Pearl Harbor on December 7, 1941.
The psychiatrists speculates that if he were to go back in time and be killed by a taxi, then he would not exist in the present and would not have gotten married etc. This is incorrect. He would cease to exist in the present from the moment he went back in time, but all the events that happened prior to this would still have happened. A proper analogy would be if he went back in time and somehow caused the death of his grandfather, then he would never be born to go back in time to cause the death of his grandfather (the grandfather paradox).