I think the comparison to the medical field only goes so far. Let's keep it in the legal field.
Say you have a small business and you have a problem employee that is always late, takes extended lunches and breaks, always argues when asked to do his job, and when he does his job, he does it poorly. You know he won't respond to warnings, but you decide to give him a chance, because at least then when you fire him, he won't be able to say he hadn't been warned. So you sit down with him and give him a final warning, that if he doesn't shape up, he's fired. He responds that your reaction is because of his race and points out what he claims to be another employee who gets favored treatment. He even complains about some insensitive comments that a couple co-workers made a few weeks back, saying he's the victim of harassment. It's all baseless. Again, you know he's not going to improve and that youi'll eventually have to fire him. But you're scared that when the time comes, you're going to get hit with that discrimination lawsuit. And what do you do in the meantime with his harassment complaint? You know it's bull ****, but can you ignore it -- if you do, will he be able to say you turned a blind eye to it.
So, do you turn to turn to the sole practitioner that's been your de facto general counsel -- the guy that helped you incorporate, that from time to time drafts and reviews contracts, that helped you purchase your current building, that will sometimes handle your past due receivable accounts? He only charges $200/hr. Or do you go to a lawyer that specializes in employment law that charges $400/hr? Does the fact that you chose a specialist mean that there's any merit to your employee's allegations?