During the fight scene between Street (Colin Farrell) and Gamble (Jeremy Renner), at one point the two grapple over a pistol; one of them manages to eject the magazine. Moments later, Street retrieves the pistol and points it at his opponent. Gamble holds up the ejected magazine as if to say "you have no ammo", but Street retorts "there's still one in the chamber, buddy." Meaning, there's still a live round in the pistol's chamber. True, but irrelevant... any modern semiautomatic pistol has a feature called a "magazine safety", which prevents the weapon from being fired when the magazine is ejected, even if there's a round in the chamber. Presumably, highly-trained SWAT personnel would know this, particularly about their own weapons.