(at around 55 mins) As Mrs. Nelson is being rushed to the hospital, the ambulance seen on the street is a Cadillac. When it enters the ramp to the emergency room, however, it has turned into a Buick.
When Dr. Tom Owen takes his nurse home, the car shown pulling up to the curb at her place is a Kaiser four-door sedan. When Dr. Owen arrives at the mine blast, he is driving a Lincoln two-door hardtop.
(at around 1h 8 mins) Tom and Helen are in the doctor's office and are having a discussion. Tom puts on his lab coat. His coat is loosely hanging around his shoulders when Homer enters. When the camera zooms back to Tom, he is fully dressed, the coat tied with a knot at the back.
In the opening scene at railroad crossing, there is a long shot standing outside of cab that then cuts to medium shot with smoke from something burning fierce in the background (rear screen projection). The view then goes back to a long shot with nary any smoke or fire to be seen.
The beginning scenes of movie show coal mine operations in Coalville, PA. The railroad caboose was from ATSF (Atchison, Topeka, and Santa Fe). That railroad never had operations in Pennsylvania.
When Tom examines the chest X-ray in Dr. Scobee's office, he talks about seeing a similar pattern in the right lobe, but is pointing to the left lung.
However, the X-ray is placed backward on the view box.
However, the X-ray is placed backward on the view box.
(at around 30 mins) When Tom tells Helen she's had enough to drink, they walk out onto the patio with the camera following, where its moving shadow falls across the door frame on the right.
When Tom goes to see Dr. Scobee in his office, Scobee is looking at a chest X-ray. The X-ray has been placed on the view-box backwards.
Dr. Owen lumps acute gastritis, intestinal stasis, and colitis into "all fancy names for indigestion". While this may be arguable for the first two, colitis is an inflammation of the colon. Indigestion may be a symptom of colitis, but they are not the same malady.