The Man Who Wouldn't Talk - S2-E3
Revealing mistake: Maria's Spanish accent keeps disappearing, giving way to the actress' natural American accent, throughout the episode. Her supposedly Spanish aunt's accent is never Spanish to begin with - it's identifiably Austrian. (00:08:00)
The Return of Roy Carter - S2-E32
Revealing mistake: When Maggie the saloon girl starts gathering the money from the floor, an equipment shadow intrudes at the left of the screen. (00:04:30)
Revealing mistake: The ground on the dueling field at the end is not only unnaturally flat, there are concrete seams visible in some spots, showing through the artificial turf. (00:24:30)