To be honest, at least in the italian version, which doesn't differ much from the english one, Ferris was starting to get sort of convinced by columbo in the end, and in fact he convinces her to talk him more about Jim and that it could help him find proof against Franklin and she does.

After she tells columbo that she doesn't believe Franklin did that and that she knows him for several years, he answers something like: even if you knew him for 100 years it wouldn't make a difference; the evidence shows this Franklin killed your husband.

Also, very interesting topic btw, I like most of those and I'd like to see some fanfiction where these final encounters actually happen!

She's in the scene, but I'd like to see a close-up of Linda in that next-to-last scene of "Most Dangerous Match."
You can see her reacting to what's going on between Columbo and Clayton, it would be nice for it to be more obvious.

That's a good one, I'd like to see that too. It would have been interesting. Circuit Bulletin