Dave :

Don't know if Bill was focusing on "pure" or HBG but here is a bit of info via ealong. I gather that up north BG stunting is a much bigger problem than down here. Bob did comment at DFW that he had encountered the problem on a number of occasions (and its result of no LMB recruitment) and how he fixed it.

ealong59
Lunker

From "Managing Michigan Ponds for Sport Fishing":

Largemouth bass and bluegills
BEWARE of this combination! It's a favorite in the South, where it can work, but it has been oversold in the North. Bass are supposed to control bluegills by predation, but it doesn't work that way in or climate The bluegills overpopulate the pond, and then both bass and bluegill have stunted growth. If you want bass and bluegills anyway, give the bass 1-2 years head start in growth and spawning. Then they may have an effect on the bluegill.

Which is why they recommend HBG over bluegill if you want to fish the bluegill.