Historians have called the way the wind plays with O'Hara's veil when she leaves the church after her wedding a stroke of luck for John Ford. Far from it, he had instructed the crew to set up wind machines to fan the veil into a perfect circle behind her head then blow it straight up into the air.
Roddy McDowall had only been in the United States for two weeks before being cast in the leading role of Huw. He had been evacuated from the UK with his mother and sister to keep out of harm's way during the Blitz.
When the miners greet their women by putting their earnings in baskets, Maureen O'Hara stopped the scene's filming once she noticed that her basket was a modern Kraft basket and not a basket of the movie's period. John Ford was so upset by being corrected in front of the cast and crew that he closed down the set and told O'Hara to wait on a nearby hill until he called for her. Fuming, O'Hara waited an hour before an assistant came to retrieve her, but was satisfied to see that the basket had been changed upon her return.