The biggest horror story involving a 70s episode involves "Old Fashioned Murder." That always came off as unsatisfying and now we know the reason why. Falk allowed a crony, Elaine May, to basically take over the whole production of that episode and there was endless tinkering, rewriting, etc. that made production stretch out forever. The "Lawrence Vail" writing credit was really Peter Fischer taking his name off the original script that he felt had been ruined completely.
The book is definitely worthwhile reading. It certainly casts a different light on Peter Falk. A lot of what prevented more episodes from being made was his own doing. He allowed the show to go way over budget by disregarding shooting schedules, spending multiple extra days reshooting and “perfecting” scenes. He hired his friends without permission and allowed them to interfere with scripts. And he was responsible for much of the excessive humor. I agree with what has been stated that the lesser Columbos are still decent, but it is a shame that certain things could have been so much better.
You have to read the book for the details. Her behind the scenes control of the episode on all levels (which was all Falk's doing) is the reason why her daughter is in the episode among other things.