This is the point where David Selby had to have an emergency appendectomy (if I recall correctly) and was in the hospital, so they had to re-write how they had intended to conclude the entire storyline.
My speculation has always been that DC wanted the series ended before he had to go out to Tarrytown to shoot Night of DS. He may have actually negotiated just how many more shows the series would run before they switched to Password. Lela was producing so the network may have set up the logistics of the final weeks with her. It would be interesting to know definitely just how it all played out.
G.
