Mike surprises Gloria and Edith by shaving his mustache in this episode. But his mustache was conspicuously absent in the episode prior to this one (The Boarder Patrol (1977)) and no one mentions it.
When Archie throws stuff off the table, then lays on top of the table, the table cloth is bunched up, and only covering half the table. When Edith comes over, and sits beside him to coax him off, and he jumps off when the phone rings, the tablecloth is straightened out, nearly covering the whole table.
When Archie and Edith are in the kitchen after Archie initially fails to notice his chair missing from the living room, a shadow of the boom mic can be seen on the refrigerator behind Archie as he's sitting at the kitchen table.