why did i get 2 bf swords in a bot game without buying them ?

Could just be an error on their end. Who knows

It happened to me with Garen. I was grinding the 200 kills for a mission and didn't go back after buying Death's Dance. I just had swiftness boots and Death's Dance. While I was smacking away at the nexus, I realized all 4 previously-empty slots in my inventory had been filled out by lmao

I got the same thing, i wish i recorded the game