I've always quite enjoyed this one. I'm not sure why but the central performances are all pretty good.
This story is hampered by having so much filler which weights it down quite a bit. The plot thread with Columbo's crash and neck injury is silly and isn't relevant to the story. The dreadful scene in the directors gallery which is just Columbo looking like a four year old as he pushed buttons also drags.
With a slimmer script this could have been right up there among the best Columbo's.
I do like the conclusion with the carousel music in the background and Columbo piling on the pressure. That works really well.
As for the "gotcha" moment, as has been pointed out in the past, as there is nothing to tie the killer to the gun, Kay has no need to get rid of it from the lift. She massively incriminates herself for no obvious reason.
I enjoyed this episode. Kay was definitely full of herself. She thought she could never be terminated. But after Mark gave her the car keys. He looks at her and says goodbye Kay. Did he actually terminate her at that point? We don't know.
On a lighter note it is never revealed who is going to take over Mark's job once he leaves to go to New York. Certainly not that bumbling understudy of Kays. Wait a minute. I've got it. It's Walter from the projection booth to the rescue LOL perhaps you could run the station
Maybe she isn't exactly admirable, but I always like her defiant attitude at the end.
"I'll survive. I may even win."
And speaking of the job, she has that same attitude just before the end when she realizes she's been fired. And it doesn't look like bluffing.
This was a good episode in my opinion. Let me address a couple of items that you pointed out. First of all I believe that the conversation between Columbo and the sergeant was the sergeant telling Columbo that they found the gun on top of the elevator. In fact later on Columbo mentions that to Kay. That they found it and replace it with a duplicate. And the sergeant did not want anybody else to hear that information. As you may recall he wanted to take Columbo in the production Booth to talk to him in private and Columbo refused that because he just messed up somebody's film.
The other thing that I wanted to point out is the over playing of the carnival music at the end. No the crew had taken a break from filming but yet they had that carnival music blasting for about 6 minutes at the end of the episode. Not quite as bad as the Volare from Troubled Waters but almost.
Hello, I don't understand at all how Columbo can trick Kay with this reel change in the projection booth. She was there to change the spool, so what? It doesn't prove that she was away for 4 minutes!