Plot hole: In the ending scene, Mike has a probable concussion from her fall, so Sully keeps her awake to prevent her slipping into a coma. They talk all night, reminiscing as Mike experiences periodic pain spasms. Their talk ends with discussion over them having another child, and then they instantly engage in an intimate moment, which would be impossible, considering her condition, and without further checkup from another doctor. Sometime later she is suddenly feeling 'cured', and they return home.
Factual error: Marjorie's tragic death: The Quinn family has her funeral in the town cemetery, where she did not belong, instead honoring her death with a vigil, then transporting her body back to Boston, to be buried properly with her Quinn relatives: A common respect reserved for dignitaries; which technically the Quinn family was/is, and soldiers.
Other mistake: In the scene where Dorothy decides to join the church picnic (just before her operation) Grace is talking to her and hands her a glass of cider as Robert E. approaches. The sky is partly cloudy, but the lighting changes slightly during the shot, and at one moment, appears too bright on Dorothy just before she sets the glass down and walks away.
Visible crew/equipment: Pilot Episode: The morning after Dr. Mike and Sully spend the night with the Cheyenne, when Wolf finds a ripped piece of Brian's shirt Sully tells the wolf to find him, and three shots later just as the camera pans toward the right, in this wideshot a crew member (presumably the animal trainer) who is standing on the hill ducks behind the bushes, near the top center of the screen. (01:05:30)
Continuity mistake: When Dorothy is doing laundry, she grabs a large piece of linen from the washtub, as Dr. Mike approaches and they talk about Dorothy hiring a caregiver for Loren, during his stroke. As Dorothy starts cranking the linen through the wringer, she stops to protest to Dr Mike about it but then turns around holding the wrung linen in her hand, though she hadn't finished cranking it out. (00:32:30 - 00:33:20)
Visible crew/equipment: When Sully visits Mike at the clinic, after dark, to console her over Dorothy's health condition. Watch as he moves past the window. You can see two control room blue screens in its reflection, alongside a boom mic, and the shadow of a long-haired crewman, who stands up, and then sits back down. Though the camera moves behind a potted plant on Mike's desk to conceal it all.