And what exactly happened to two fed scientists? Did Gem not feel like saving them? Has she grown, through knowing our specific intrepid Three?
That was the idea. Gem learned self-sacrifice from their example. I guess Linke and Ozaba weren't as selflessly devoted to each other as Kirk, Spock, and McCoy were. She probably tried to help them, but wasn't able to overcome her self-preservation instinct enough to risk her life for it. Also, the Vians hadn't yet had Kirk come along to give them a good scolding, so they probably took their tortures too far, as they almost did with McCoy.
Pretty plausible. Another thing I like: Kirk doesn't go on and on. Makes the point. Vian still has some humanity it resonates with. Reminds me of the great scene in Jedi where Luke gets through to Darth as David Prowse turns his head just slightly. You can really imagine him going, "hmmm."