Bank/Inventory Space Glitch?

I don't mean to get anyone's hopes up or misguide them, but I stumbled upon something that might be found interesting. I was arranging and moving around multiple items between my bank and inventory, and I honestly have no idea how I did it as I wasn't really paying attention to what I was clicking and whatnot, but after moving a random item or swapping a pair of items (as I was doing the whole time), I noticed right afterwards that a space opened up in my inventory. It was 200/200, and my bank was 250/250, but it became 199/200 and 250/250. I didn't move any AC-items into my bank, as I didn't have any in my inventory. I spent the whole past hour trying to recreate it, but I couldn't, which sucked. Maybe one of the geniuses on here can figure it out? Wish I had been paying attention, but hey, one free bag space is pretty cool.

Dunno, maybe I'll look into later today.