When Leighton is wheeled from the operating room to the elevator, the floor is visible. There is no break in the solid floor as one would normally see upon entering a real elevator. Obviously no elevator was actually used and the elevator doors were probably moved by hand.
During the surgery, an assistant mops the surgeon's brow, breaking aseptic technique, then hands the surgeon a sterile instrument. Later, the overhead surgery light is adjusted with a gloved hand, once again breaking asepsis.
Strings or wires can be seen attached to the space ship to move it across the sky and make its landing.