There's discussion on this, beginning with your initiation of it in your post of March 31.

No worries, I was just redirecting to related discussion. And elsewhere discussed in the forum, like Clive below, from the very beginning, when Abigail claims it must have been an accident, Columbo's on it. Thus, the episode's greater strengths are in the interactions between Abigail and Columbo; the weaknesses in her story and behavior feeding the duel between somebody that writes murder stories and someone that solves them. The light bulb moment is well done... except for the oddity that nobody changed the bulb early on so they could get a better look at the place where the body was found.

From the very first scene Abigail thought she had the intellect to outsmart any investigator. Being a crime novelist she honestly imagined she had what it takes to get away with murder. Yet from the moment Columbo speaks to her in the study, she is put under pressure, all those little loose ends just don't add up for Columbo and he immediately suspects foul play. By the time of the scene with the keys, Abigail realises Columbo is onto her, and she's now floundering, she's flummaxed, and she cannot cope with the pressure. So in a moment of rash stupidity she makes up a silly story about finding the keys. Alas this confirms Columbo's suspicions even more and places Abigail in the spotlight once and for all. Columbo is never sidetracked in this film, he knew the killer was Abigail, he just had to prove it and the final scene, where Abigail is asked to read out the killers name (hers) is a masterpiece. I always thought Ruth Gordon would have been great in another episode of Columbo, she was a great actress for this type of role. Try to Catch Me is my favourite Columbo film, even the musical score was exceptional.

Ruth Gordon WOULD have been great in other episodes. However I must dissent on the musical score. I didnt care for it.

With regards to the keys Veronica by holding them was in a perfect spot to write her own ticket. I wonder what she thought when she returned to the cruise ship cabin to find her boss gone. And her out of a job.

I've mentioned it 2-3 times already, but there's also the way that scene is filmed. It looks like she could've gone ahead and dropped the keys in the water without Columbo seeing her do it.
And even if he HAD seen it, it might've been very tricky for him to do something about it (even for the person who got a whole cornerstone dug up in BLUEPRINT FOR MURDER). It might have been as easy as just hiring divers, but maybe not.

Thinking about this more carefully it occurred to me Abigail was fortunate that Edmond left his car keys on the table, because if he had been locked inside the safe with them, he could have scratched messages all over the interior of the safe - too obvious by far. The keys were always going to be part of the plot, the Achilles heal for Abigail. She didn't foresee any problems after murdering him, except those darned keys. She couldn't think what to do... and by burying them in the butt tray she then left herself wide open to suspicion and ultimately blackmail by Veronica. Some viewers may have imagined Abigal making a clumsy effort to throw them in the sea. I argue this was a clever scriptwriter ratcheting up the pressure on our main suspect. Abigail was clumsy and offered a typical stereotyped response about old age and forgetfulness. Just as she did in that superb final scene and of course Columbo was far too professional to be taken in by her pleading.