Buzz Conway (Jack Weston) escapes from Napoleon Solo by going out a window and edging along the ledge, moving to his left with his back to the wall. But when he comes to Narcissus' (Barbara Bouchet) window, he is now moving to his left while facing the wall. That's not possible unless he turned and went back past Solo's room.
Narcissus is shown lighting her cigarette two times in a row.
Mr. Elom says they have run into an unusually hard layer of sediment. and his engineers need help to drill through it. By its nature, sedimentary rock - sand or silt compressed over time - is not very hard at all, and would present the least difficulty of any rock to Thrush's drilling.
When Buzz Conway is on the ledge looking into Narcissus' room the backdrop behind him is just a blank wall with no scenery painted on it.
Just after the main titles a microphone can be seen in front of Solo and Mr. Waverly as they walk down a hallway.