I just stole an item from the shop using the directional pad's grappling hook. He didn't mention the firing at all just called me a thief and ejected me. It may be because I was very close to the item, and the steal was fast enough for him to notice it before the bullets.
So...the "directional pad" gun is glitched as hell.
I was fighting the Bullet King in floor 1 - I had the directional pad as my only new weapon. I ran out of ammo, and it turned into the chest - the bullet king at the same time threw a molotov at the chest location, couldn't get to the chest (brown) for a while. It seemed to be slightly glitchy in appearance after the flames cleared, I opened the chest while fighting BK, and...the screen dimmed, and I entered the next floor??? BK still had a third of his health bar left, I just glitched out of the fight and out of that floor entirely.