"I am concerned that even the docs are using the term "BB"...BB shots are MUCH larger than birdshot."
Probably just unfamiliarity with shotgun terminology. There has been a lot of that. I wouldn't pick nits too seriously...there's going to be a lot of misinformation.
If they were hunting quail, they wouldn't have been using BB shot.
You can't get BB shot in a .28 gauge shell.
Nor, buckshot, as had been widely reported.