Other mistake: In episode 367, there is a continuity glitch. Vicki Winters travels back in time from 1967 to 1795 as the result of a 1967 seance gone awry. Vicki is disoriented and confused by her surroundings and is made to lie down and rest in a bed. There, a granny square blanket is placed over her - the exact same one as seen in earlier 1967 episodes at Sam Evans' house, draped over his sofa; the green granny squares around the perimeter of the blanket are a dead giveaway that it's the same blanket. Either there was a mistake made in that they hoped nobody would notice that this same blanket appears over and over again in the series (it appears again in the series in unlikely places in episodes even after #367, as well), or it's a mistake to try to pass it off that this 170-year-old blanket was somehow still in perfect condition in the future, in 1967, at Sam Evans' place. Either way, it's a mistake.
Audio problem: In several episodes, there is a shot of the grandfather clock in the downstairs hall. When the camera comes in for a close-up of the face of the clock, a chime can be heard. It is the Westminster chime, which normally sounds on the quarter hour (4 notes), the half (8 notes), the three-quarter (12 notes) and the hour (16 notes plus the number of hours). However, on several occasions, the clock is off-strike, either by the number of notes it chimes or chiming when it normally would not (for example, at 11:20).
Other mistake: 1795: A black-and-white cat, supposedly the transformed Joshua Collins, was completely uncooperative in every scene he was in. He always started out on a bed or a chair, but got up and left every time, usually forcing the camera to pull in so that the actors could pretend the cat was still there.Jean G