Yes, "Last Salute..." was very strange. I think this certainly had the most flimsy "Columbo moment" with Swanny saying "T'isn't!" to the sound of the ticking watch.

As for "Forgotten Lady" it wasn't really a case of letting her off. Her medical record showed she only had a month or two left to live, so it probably wouldn't have even got to trial - plus of course she had no recollection of murdering her husband.

Some of them, like "Identity..." did seem to try something different, but didn't necessarily work

I think Identity Crisis is pretty solid. It does, along with A Case Of Immunity, introduce the notion of Columbo being thwarted, albeit momentarily, by bureaucracy. Perhaps it was or wasn't the case back then but that's definitely a rather cliched obstacle for "maverick" detectives on TV and in film these days.

Crucially though, in each case, it's more than the usual "I'll have your badge" type threats and it's how Columbo overcomes this which is vivid and consistent with character. In Identity Crisis, Brenner brings his CIA boss down on Columbo. Instead of being intimidated though, Columbo uses this intervention to confirm what he already suspected about the state that the victim's body and the likely assailant. Brenner even recognises this as the key to Columbo's tenacity which, as a fellow warrior perhaps, the double agent admires.

In A Case Of Immunity, Columbo uses his judge of character and intel gleaned from the protesters in relation to both Hassan and the King to devise an audacious sting. First of all, the King's open mindedness in allowing the charade and, of course, Hassan's hubris in being protected by diplomatic immunity and the belief that Columbo might give up on a murderer for the sake of his job. This bears fruit when Hassan can't wait to deliver himself into the Lt.'s custody and compliments him by not even reading the confession which he has already prepared. I love also how Columbo is as coy about accepting Hassan's plea for relative sanctuary in the arms of the LAPD as he normally is about accusing or implicating anyone.

Another excellent example of this is "Friend in Deed" when it's the Deputy Police Commissioner who's the suspect.

I mean he gives himself away when he refuses to consider the clues Columbo comes up with about the fingerprints on the phone and the night-dress.

He constantly orders Columbo to concentrate on it being a burglary gone wrong, and then Columbo actually uses the burglar to help frame the Commissioner.