Cryolater without being a master lockpick
It's a glitch; the only reason it worked is because the cryolater wasn't in a normal box. It was in a display case of sorts, so its world model was already present in the game. It's not like a normal box where the item's world model isn't present while in the box. If there are any other display case like boxes in the game where after being opened, the item is just sitting there to be picked up rather then from an item list like normal looting. I imagine the same glitch would work.