Much like the characters they are portraying in this episode, Doris Roberts and Ron Glass really did costar on another crime show - they both played characters on the 70s show, Barney Miller.
This episode foregoes its traditional simple display of end credits by running them over a karaoke scene that was part of the story.
Marion Ross's character points out that the residents present were all involved with the TV show "Prognosis: Homicide", which is clearly a tongue-in-cheek takeoff on the name of Dick Van Dyke's 90's series "Diagnosis: Murder".
A far more likely explanation for the address 1066 Hastings Street being used, is that many Movie/TV Studios, Actors Agents, Photographers, Writers, etc have offices in the building at that address in Vancouver B.C., aka Hollywood North.
The address of the apartment building is 1066 Hastings Street, an evident reference to the Battle of Hastings in which Duke William of Normandy defeated King Harold Godwinson, which took place on 14 October 1066. The battle marked the permanent end of Anglo-Saxon rule in England and the decline of the Old English language as it became contaminated by French.