Do you honestly think that Muskie, Mitchell et al have tied up all of their credibility with Hyde?
There is indeed a critical mass of rumble necessary, a threshold that must be reached, and then I think you'll see people distance themselves, claiming "regrettable ignorance" and the indignities of being misled.
Taking a case on spec, i.e., contingency, usually runs about 30% or a third, depends...
Some attorneys chomp at the bit for cases that may end up being ground-breakers, or stand a good chance to be cited in subsequent (other) ones, i.e., setting legal precedent.
It's not always just the money; there's also the "fame," and let us not forget plain old wanting to do the right thing. Believe it or not, that is why a substantial percentage of people usually go to law school in the first place.