Visible crew/equipment: (Ep. 2) When The Doctor, Jo, and Dr. Tyler are taken into Omega's palace, in the first shot of the multiple passageways (right before Jo says that it looks like Aladdin's cave) the curved chalk actor's mark is visible on the floor, then we see it again in three following shots. Note that when they're all escorted further inside, just as Dr. Tyler comments about the matter/anti-matter not making sense, Jon Pertwee looks down, presumably to make sure he hits his mark.
Visible crew/equipment: As the energy being moves down the city sidewalk, we see its shadow on the concrete. Right beside that, however, we can also see the distinctly-shaped shadow of the camera. (00:35:00)
Angels Travel on Lonely Roads (2) - S1-E22
Visible crew/equipment: After Kimble finishes stacking wood in the barn and is putting his shirt back on, the boom shadow moves across the wooden chair hanging on the wall behind him. (00:25:00)
Who Killed Avery Lord? - S1-E23
Visible crew/equipment: After the woman in the negligeé goes back into her apartment, a crew member's shadow appears on the corridor wall. (00:42:00)
Visible crew/equipment: In the 1987 Mt Rushmore conclusion, when Robert knocks Duke out with the infamous WSB chop, the put Duke on the couch. When Sean is tying Duke up is apologizing to him, at the end of the couch for several seconds (behind Duke's head) you can see the camera man moving.