Maybe Jones has a special license.
Most likely they are big enough to handle the expense of destructive testing to prove they are VHS-free, which will let them ship interstate. Smaller places are hard put to right off the number of fish that must be destroyed to satisfy the authorities that they are VHS-free.
IIRC Cecil said it used to be 60 fish (of each species to be shipped interstate) once a year, but that the number and frequency have been increased. It is very hard for a small fish operation to sell interstate in the Midwest now.