You are correct that they are all later
episodes, however I must admit that the
finale, "The Conspirators" had Columbo
return to the modest detective we all love
so much.
BTW-The British certainly could use someone of his talents now to track down those responsible for the heinous attacks that occured there. It seems they have very little evidence although the suspects are probably known.

You are right about The Conspirators...it seems he came back down to earth again.

More importantly, it was such a tragedy what happened in London. I am praying for the families affected by this senseless act...

Hi, I think it needs to be noted that there could be a reason why this particular episode is so shoddy (my apologies to those who've enjoyed it, but my feeling is that this one is bobbins). If memory serves me correctly, it was directed by Patrick Macgoohan, and he has been known to take liberties with scripts. He directed the final episode of The Prisoner with the same callous disregard for the form, style and substance of that series, and methinks he did the same with Columbo.
Or maybe not; that's my excuse anyway.
Incidentally for our non-English Columbophile friends, bobbins=rubbish.
Ta ra,
Sita xx