At 1:14:15 in The Voyage Home, Scottie drools on his shirt.
Scottie is trying to beam Uhura and Chekov from the Enterprise (the aircraft carrier, not the starship) to the borrowed Bird of Prey and in his excited state to communicate with the stranded Chekov he…. drools on shirt. Seen this movie a thousand times as it's the only one my non-trekie friends and family enjoy and I've never noticed this.
Also, after the two whales are sent away Dr. Jillian Taylor slaps her boss and in a frenzy storms out. From her coworkers point of view she disappears forever after this. What must they think about her dissapearance?