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 Grills’ 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...
Continuity: After getting into the fight with the two Korean men, Ludlow has blood on his forehead. During the scenes where he bust into their house, in some shots he is seen with the blood on his forehead but in other scenes there is nothing on his forehead.
Continuity: When Ludlow shoots the Korean guy who was sitting on a toilet, he falls and we see that he has his pants on and the toilet seat is actually down. Later, when Ludlow plants the weapon on the guard at the desk, we see over his shoulder that the toilet seat is now up.
Revealing mistakes: When Ludlow is tied up and being shot at by the other cops outside the house in the hills, the red plastic cases of the squibs are clearly visible as they explode around him.