I wasn't verbose enough I guess. I made the initial determination that it was a CBA by the number of rows, but I've heard of 4 row diatonics, so then I looked to see how much he was moving the bellows in and out. Mostly, not much, which told me it was a CBA.
I'll be even more verbose. Towards the beginning of the video, he was doing some amount of in and out, which confused me. Now I know that he was just trying to keep the bellows close in, in anticipation of a long unbroken run to the out site.