Robert Comsol wrote:
. . . Spock would have neither passed for a Caucasian or an African American or a Hispanic. On the other hand Boris Karloff had been portraying the Chinese character of Dr. Fu Manchu
on film, so Kirk might have hoped the policeman had seen the films to buy the story (or that
might have been the thinking of the TOS producers. There is some facial resemblance between Boris Karloff and Leonard Nimoy).
That's certainly an interesting take on Kirk's line about Spock being "obviously Chinese." I never thought Spock looked at all Chinese!
In any case, what makes the scene funny is that Kirk's frantic ad-libbing to try to explain Spock's odd appearance is totally unnecessary. All the policeman cares about is that he's just caught two thieves red-handed. Hell, he's probably encountered weirder looking characters than Spock in the line of duty.