Tommy Campbell is a good drummer who was not always up to the demands of playing with Sonny. I've got a concert recording of a night where Sonny's on, just letting it flow, and Campell audibly runs out of energy about halfway through Sonny's solo, just falls away. But Sonny keeps going, bumps it up a notch, actually, as if to say, "hey, if you can't hang there, how you gonna get HERE?".
A lesson learned for the young man, one would hope (and one would also hope that that's why Campbell was hired in the first place, to be taught some lessons).