How did I lose a pistol? Pickpocket or saved game bug?

I'm playing Fallout 2 for the first time, and got my first firearms - a pair of 10mm pistols, with different amounts of bullets in them. I equipped one, topped up its bullets, and left the other in my pack, and removed its bullets. I walked around The Den for a while, and may have swapped an item or two in my hands, and saved my game, and stopped playing.

Later I restored my game, and noticed I didn't have a pistol equipped. I also still only have one in my pack, with no bullets in it. Somehow I lost the loaded pistol.

How could that have happened? Are there some pickpocket characters who can sometimes steal something from you? Or is there a bug with saved games that can remove something from your hand? I suppose it's possible I managed to leave it somewhere by UI accident, but I tried looking in the shelves, corpse, and shopkeepers I remembered visiting recently, but didn't find it.