Factual error: When the hitman shoots the Mustang's windshield, the damage is not consistent with a shotgun blast at close range. The windscreen is actually hit in two separated areas. Winchester would be very unhappy if their guns really shot like this.
Suggested correction: It's fairly realistic for a shotgun blast to be scattered like the one to the Mustang's windshield. Shotguns throw a loose pattern that is often random in their impact.
Factual error: "Ice Station Zebra" is one of dozens of films which make the mistake of showing people carrying rifles such as M-16s with the magazines inserted. In the scene where Marine Captain Jim Brown arrives at the submarine via helicopter, he comes aboard passing his M-16 through a hatch with the magazine inserted, barrel first - a double safety violation. I first saw the movie in a Marine Corps base theater, and all of us yelled at the screen when we saw that.
Factual error: Rosemary calls Dr. Hill from a pay phone and says, "The baby's due on Tuesday, you remember you told me June 28th" (and June 28th 1966 does fall on a Tuesday). In the previous scene in Dr. Sapirstein's office his receptionist is making an appointment "next week" for a patient and that date is "July 10th" indicating that if Rosemary is due on June 28th (which she says is next Tuesday) the dates do not match and it must still be the week of June 20th which is at least two weeks before July 10th. (01:44:45)
Factual error: The truck's gas tank is said to be empty, but is able to explode spectacularly later on. An empty gas tank may spout a jet of flame, but will not have enough force to rupture and damage the truck, a full tank of liquid gas will not burn unless vaporized. Simply put the truck would not explode in that Michael Bay fashion.