I share your admiration of early TOS Kirk as a character.
I am not expressing admiration. It's so frustrating to me that so many people assume that the only possible angle from which to approach a discussion is the angle of personal preference or emotional bias. What I'm trying to do is to evaluate the situation objectively, purely on the evidence. And when people assume I'm arguing from bias or have a personal agenda, it keeps me from getting my point across.
I'm not saying the way Kirk was written at the time was "better" or "worse" than how he later came to be perceived, because that doesn't have a damn thing to do with establishing the
facts of the matter. I'm merely saying that it's how he was written.
He was very sophisticated for a sixties hero and by no means cocky, arrogant, or lascivious. Still - if Helen Noel was tipsy and offering it on a plate - it must have been challenging for the writers to resist - he wasn't a nun...
"Must?" You keep using these words that allow no possibility of ambiguity even though what you're offering is merely unsubstantiated opinion. There's no "must" about it. It doesn't even make sense given the preponderance of evidence. Eve McHuron threw himself at him and he was unmoved. Rand made it clear she was willing and he didn't respond. The writers made it clear that they had no problem "resisting."
Kirk was written as a professional military man. If a member of his crew was compromised by alcohol and making inappropriate advances on him, he would not take advantage of her. That would practically be rape. At the very least, it would compromise their ability to function as crewmates afterward. And first-season Kirk was absolutely committed to the good of his ship and crew above all else, and would do nothing to compromise that. It wouldn't happen. And the dialogue makes it explicit that it
didn't happen.
Given Demora's age, wouldn't she need to be born during the 18-month refit period?
Demora's age isn't clearly established, but Peter David's novel
The Captain's Daughter does have her conceived sometime during the 3-year span between the 5-year mission and TMP. (It was odd that TMP had Kirk as Chief of Starfleet Operations for 2.5 years but made the refit period only 1.5 years. What was the
Enterprise doing for that first year or so?) There's also an issue of Marvel's
Star Trek Unlimited that offers the alternative interpretation that Demora was born in the final year of the 5-year mission. (Their TOS stories were set during the 5YM but gave Scotty a moustache and Chekov lieutenant's rank, suggesting they were close to the end.)
Do we know what really happened? No. Do we know that both parties were being totally honest when they said they only danced and talked about the stars? No, we do not that either.
Yes, we do. As
Nerys Myk says, the whole point of the scene was for Helen to implant a false suggestion in Kirk's mind, something that was unusual and counterfactual enough that they could both be certain it was a creation of the neural neutralizer rather than an actual event. Just making Kirk think he was hungry wasn't enough proof for him, because he actually could get hungry. It had to be something that he
knew could not be true. That alone should prove beyond all reasonable doubt that nothing happened between Kirk and Helen in real life.
All we can take from the scene in the transporter room is that the sexual and interpersonal tension between the two could almost be cut with a knife.
That's a subjective reading. There was attraction and embarrassment, yes, but I don't see it being that overwhelmingly intense.
Plus, the scene plays much better if something may have happened, characteristic or not.
But what constitutes "something" in this case? Again, it's imperative to be able to look at
ourselves as we assess something, to consider how our own preconceptions and biases are shaping our interpretation -- and how those assumptions differ from those of the people who made this television episode. Remember that this episode was written and filmed 45 years ago, a more innocent time in some ways. Remember that they didn't even show married couples sleeping in the same bed on television at the time (except for Gomez and Morticia Addams). In '60s TV, sexual tension would've more likely been in terms of attraction, making out, the
potential for sex, than a sign that the two people involved had actually
had sex. So just flirting and attraction could've been enough of a "something" by the standards of the day -- especially if it was professionally inappropriate. Especially if Kirk was the kind of man he was written to be at the time, a serious, work-driven man who resisted romantic opportunities. For a character like that, being that attracted to Helen would be more than enough of a big deal to make him react the way he did, even if nothing had actually happened.