Just checked - I forgot how much the camera moves(shakes) during this film.

During that scene (Kirk & Scotty are brought up to the bridge after beaming aboard the Enterprise while it's under warp - starting around 1:29 on the digital copy) they cut back/forth between Spock and Kirk numerous times. Between the cuts & the shaky camera, Spock's shoulder appears at numerous places in front of the guy in the background.