Star Trek can make as many new series and movies as they like, and still nothing will ever truly beat the golden awkwardness of this one shining minute of dialogue.
Spock, the first officer whose advice was always effectual, possessed a strength of understanding, and coolness of judgement, which qualified him to be the counselor of the ship’s captain, and enabled him frequently to counteract, to the advantage of them all, that eagerness of mind in Captain Kirk which must generally have lead to imprudence. Spock had an excellent heart, positioned somewhere near his kidneys; his feelings were strong, but he knew how to govern them: it was a knowledge which his captain had yet to learn, and which one of his fellow crew members had resolved never to learn.
Dr. Leonard McCoy’s abilities were, in many respects, equal to Spock’s. He was sensible and clever; but eager in every thing; his sorrows, his joys, could have no moderation. He was generous, amiably cynical, interesting: he was everything but logical.
So people make fun of the Kirk shirt rip in Shore Leave because it is so blatantly independent of the fight with Finnegan
See:
then:
But what most people fail to acknowledge is that the Shore Leave planet is there to suddenly create things you are thinking about, rather than obey the laws of reality.
Which means that Kirk was thinking about fighting Finnegan, so he appeared:
Which also means, in the middle of the fight, Kirk must have thought: “Man, it would be so cool if my shirt ripped off right now,” leading to the inevitable:
So since we’re fairly certain now exactly what Kirk thinks about during fights, we can continue to laugh at his shirt rip in Shore Leave, but make sure it’s for the right reasons: not so much continuity error, more actually being Exactly In Character.