When the alarm clock goes off, the sound is of a large school bell and not an alarm clock.
When Endora and the British policeman who is supposedly in suspended animation are sharing a two-shot, he is clearly having some trouble staying absolutely still, unlike when he is shown on his own as a still image.
When Samantha wakes Darrin up at 8:30am, Darrin asks Samantha what time it is she responds 8 o'clock.
In the full-screen shot of the ad Darrin creates to promote the rally, the ad reads, "Be sure and bring all your friends." But neither Darrin, Samantha nor Darrin's friend Dave recognize this when Dave suggests the ad could be improved by having it say to bring your friends.