From a writing standpoint, you would really have to contrive something. Rest of bridge crew unconscious and turbolift broken or something. BUT - think how many times Spock has been in command and McCoy is always needling him. Turns out Spock is always right. Now would be a good character development moment for McCoy to realize how hard it is, possibly screw up and recover right at the lost moment or something. (Or better yet, some real loss occurs, but probably not in '60s TV.) This is NOT a bad episode idea, frankly.