The regulator also needs a broad view of "expert" and affected party. For example, when regulating mortgage practices, first in the room is bankers because they are affected and experts. Alas, the ranks of the not invited include average people who have a mortgage or hope to get one. Also absent, people who were foreclosed on. They too are affected and could be considered experts on their own personal situation at least.
A good regulator will understand that. Alas, I know of no algorithm to choose a good regulator without resorting to recursion and tautology.