So he made a lot of money and worked with some big-name clients. Obviously, it can be done. But really, anyone who becomes an economist with the goal of making a lot of money doesn't understand opportunity cost well enough to become an economist.
Plus, let's be honest. 95% of the work that litigation consultants do is just shuffling money from one group of rich people to another. There are very few truly welfare-improving efficiency gains to be made from consulting, and most of those gains are swallowed up by the lawyers and the consultants anyway. The best thing most consultants can say about themselves is that they are a transactions cost. With all due respect, who gives a fuck?