Visible crew/equipment: Just after Tarzan goes under the stone door, he finds the torches dropped by the bad guys. The flame from one of the torches is reflected in the camera lens, and was caught on tape. It looks like a single, unattached flame is hovering on the stone wall nearby. This is made even better when Tarzan picks up the torch and then drops it, the reflection follows his movements precisely.
Plot hole: When Tarzan comes to the hotel to visit Jane, he overhears the bad guys threatening the hotel clerk into giving them Jane's room number. Tarzan then has time to go into the streets and study the hotel for a little while (coincidentally just when Jane happens to appear in her window), climb to the second story and through her window, have a romantic reunion with Jane and explain what is going on before the villains have managed to ascend the one stair from the lobby.