In the last scene, when Vaughn takes the rifle, he flips the front scope's cap but he forgot to flip the bottom one. The cap is clearly visible.
When Lauren says "even take the fall" her lips don't begin to move until after she's done speaking the line.
When Sydney engages Sloan's bodyguards in his Kyoto home; she fires her handgun until it is empty and the slide is locked back. She pulls the trigger again and a gun shot is heard even though the weapon is empty.