WASHINGTON – Only one of the five people killed in the raid that got Osama bin Laden was armed and fired a shot, a senior defense official said Thursday, acknowledging the new account differs greatly from original administration portrayals of a chaotic, intense and prolonged firefight. The sole shooter in the al-Qaida leader's Pakistani compound was quickly killed in the early minutes of the commando operation, details that have become clearer now that the Navy SEAL assault team has been debriefed, the official said, speaking on condition of anonymity because he was not authorized to speak on the record.