Conflicting themes I noticed

I’ve been rewatching all L&O lately and recently I came across 3 very particular episodes. So first there was the episode with Serena deceiving the guy during a hostage situation and getting in a lot of trouble for it. Well later on I saw the next 2 episodes where Micheal Cutter also uses deception only he uses it to secure 2 convictions. First he got the guy who believed he was JFKs illegitimate son to confess by tricking him with fake paperwork. Then in the episode about systemotics, cutter at the last second lies about being part of the cult which resulted in another confession.
I can’t help but wonder why was that deception acceptable but using it to save someone’s life was the ethically questionable moment they chose to focus on.
I mainly just wanted to bring this up with other people who mainline this show just to see if anyone else has some input.