Either way LIVE ammo rounds should not have been on the movie set, and apparently the crew had been using the gun(s) for target practice by shooting bottles in the desert with LIVE ammo, add to that the reported apparent lack of safety on set, the assistant director Dave Halls handing Baldwin the gun and saying "cold gun" without double checking the weapon, because he apparently thought the armourer Hannah Gutierrez had checked it, which she clearly had not, and finally Alec Baldwin, after being handed the weapon, did not double check that it was safe. Regardless of what happened in the time before the weapon was released to the set for use, the minute it was on set, it was the responsibility of every person in the chain of custody to double check the firearm for safety.