Continuity: The position of the sun changes in the last scene.
Continuity: When Captain Biggs sits across from Ludlow at Ludlow's desk and begins conversing with him, Biggs' necktie alternates from being outside of his lapel to under it, even though he does not move.
Crew or equipment visible: When Ludlow and Diskant are at Scribble's house, just after beating him with the telephone book, someone disappears through a door in the background and in the next shot the door moves and closes. If there was supposed to be someone else in the house someone would have noticed and/or mentioned it...