Cyranoise de Bergington - S5-E8
Other mistake: During the opening scene, Cliff is in his home office, located in the basement of his home. The phone rings. He walks over to his office desk, then presses the speaker button. An unfamiliar female voice is heard speaking, as she states that someone is there is see Cliff. Who is that woman? Where is her office desk stationed? She is never heard, or seen, ever again within this episode, and throughout other episodes, prior or after. This is S5E7. This website has the season and episodes mismatched. (01:19:00 - 01:39:00)
Suggested correction: It sounded like Clair to me. And in regards to who that someone was, it was Rudy. So it wasn't as if it was Dr. Huxtable's secretary announcing a patient, or a secretary who didn't know who Cliff's kids were. It's easy to picture Clair acting like a secretary for her daughter's sake so that Rudy could come in and talk to her dad while he's a work, without Rudy just running in and disrupting him. Plus, his phone didn't ring, it was the intercom that Clair would have used from another phone in the house.
Clair is not seen speaking into a speaker, at any time, during any episode, throughout the entire show's existence, and that woman's voice does not sound like Clair's. In addition, Cliff exchanged with 'the mystery female' in a professional manner/tone of voice, like a boss would to an employee, an not in his usually playful, loving voice, that he normally speaks to Clair with.