Well . . . I'm looking at the code right now, and Phoenix Blaster literally doesn't even exist in the same section that designates the drops for every single enemy drop in the game.
I've seen items being set incorrectly before, its a mistake that happens, but literally 100% of the drops in the game come from this section of the code, and Phoenix Blaster isn't in it anywhere (being a crafted item). I even checked the special section for "the random junk you can find in slimes", and there is no sign of it there either.
So I can't see this happening by any normal "bug" means.