When Alfred is in the ambulance and notes that it was tough for Lucas to come down to the hospital, his position changes depending between the shots looking back at Lucas and the closer shot of him.
1st year medical students are generally in their early 20's, not in their 40's with gray hair as in the movie.
When Dr. Runkleman is undergoing surgery near the end, there are several closeups of an electrocardiograph as it monitors the procedure, but there are no wires connecting it to the patient.
When the safety pin is being removed from the patient's lung, it is obvious this being done with the instrument and pin on top of a projected fluoroscopic image of the lung.
First, there is slight movement of the pin as the instrument touches it, next the surgical instrument appears to be entering straight down from the top of the lung, not following the trachea and bronchi, lastly there is no movement of the lungs on the fluoroscope.
At 2:00:00 when Luke walks over to Al's car, he has his cigarette in his left hand when he opens the car door. When he sits, the cigarette is now in his mouth.
When Lucas is at the ranch at night, a horse whinnies without moving its mouth.
When Lucas and Kristina visit "Greenville", which is supposed to be isolated and rural, they pass a truck with "Reseda Boulevard" on its side. Reseda Boulevard is just a few miles northwest of Hollywood.
As a nurse, Kristina would have known that she should avoid being exposed to a typhoid patient while pregnant.
At the beginning, Olivia de Havilland's "Swedish/Minnesota" accent is barely discernible but becomes much more pronounced later.
Dr. Clem Snider is a doctor who is a political appointee at the hospital where Lucas Marsh works. Snider freezes during an operation and does not recognize the symptoms of typhoid in one of his patients. Marsh grabs him by the neck and calls him incompetent. Snider says Marsh is crazy. However, when Marsh's mentor suffers a heart attack, Marsh asks Snider to assist him in performing open heart surgery.