Revealing mistake: There are several places where Mindy does not favor her "sprained" ankle. The most noticeable is when she and Mork are about to open the trunk, she shifts her weight from one foot the other a few times.
Revealing mistake: During the sword fighting scene, the split in the couch is visible before it actually gets split. Also in this scene, when Xerko has Mork at sword point right before Bickley comes in, Mork's ribbon is cut in the close up, but in the long shot, it's intact. Xerko will later cut the ribbon.
Continuity mistake: In the scene where Mindy shows Mork the differences between herself and the mannequin Dolly, Dolly is in a different position in every shot. Her legs are sticking straight out when she first 'sits' down, then bent down, then straight out again, then closer together and the left shoe is on backwards, then her right shoe is backwards, then she's tilted to the left and finally she's sitting straight up.
Continuity mistake: In all episodes, shots and zooms from outside onto Mindy's apartment show a different front of windows than from the inside. That includes size (width vs. height), glass patterns and coloring, and distance between single windows. Even the glass patterns seen from outside occasionally change from episode to episode. From the inside there is a door (to the staircase) between the small window to the right and the bow-front. From the outside, space for a door or a staircase is completely missing.