Other mistake: The map behind the officer is of Southern California. The series is supposed to be set in the NY tri-state area. (00:12:45)
Other mistake: At the end of a scene showing the dog, the scene is reversed (mirror image) for a moment. (00:08:50)
Answer: The original diamond and white gold heart necklace was given to Elizabeth Montgomery by her then real-life husband, William Asher, who also directed the show. She wore it in nearly every early episode. When the necklace was lost or stolen about mid-way through the series, Montgomery had two replicas made from rhinestones. She wore either one of those for the rest of the show's run.
raywest ★