Yes, season five found the Columbo films changing slightly. In many cases the shows seemed a little more experimental, and perhaps a little less clear cut, with regards to the plot, and the motives etc. 'A Case Of Immunity', and especially 'Identity Crisis', seem a little less obvious with regards to motive, and even to a point, 'A Matter Of Honor' which isn't really simply about the murderer being wronged, in some way. 'Last Salute To The Commodore' also is by far the show's biggest departure, of the seventies series, anyway.

What's great about season 3 and 4 also is perhaps the fact that some of the murders possess a degree of sympathy, perhaps, on behalf of the viewers. The Donald Pleasence, Johnny Cash, and Patrick Mcgoohan characters. especially, unlike many of the murders from the early seasons, may not have been truly bad people.

I believe too that season three may have had the better films than season 4, excepting perhaps the more mediocre 'Lovely But Lethal', and 'Mind Over Mayhem'. Season 4 is great, but i think the padding on 'An Exercise In Fatality' does blunt its effectiveness somewhat. I believe The Columbo Phile makes a very valid point here, on this occasion.