Good points. I think that the key point is that a non-deaf murderer would have turned the machine back on to finish the job as it were. But as you say, it could have been an accident, and how did Clayton know the machine was on in the first place...I will have to watch it again. Best thing about this episode is the snails and also Columbo phoning the vet and making Clayton think he is phoning the hospital.

I sometimes feel that this episode doesn't feel "grounded". By that I mean we never see the killers home, it is all set around a hotel and a hospital, and this gives it a transitory feel which other episodes don't have

That's a good point about the 'grounding' issue, Paul.
I mean, you can't really call a hotel lobby your home!!

I like the concept of a deaf murderer vs. a non-deaf murderer, but the problem is Clayton was the ONLY suspect. There were no non-deaf suspects to rule out which makes the clue unnecessary and meaningless.

Columbo had two options. It was either an accident or Clayton did it. The deaf man clue proves nothing.

As Jim Ferris was saying just before he was shot...This is the last time. That I can promise you.

If Clayton had heard the machine go off and turned it back on again, wouldn't that have completely destroyed any possibility of it being an accident? It would then be an obvious murder, and Clayton would be the obvious suspect.

Good point Cassa...I never made that connection!
And you are right E, the final clue does appear to be meaningless. I think it just sort of pains us sometimes to admit that a Columbo episodes has its flaws.

I agree, Paul. I think the reason why I am so bothered by this episode is because there is so much good stuff there, but it doesn't come together in a satisfying way. The ending is somewhat clever, but there are too many holes in Columbo's logic.