A lawyer who apparently underpaid his ex-paralegal by $300 now has to pay $100,000 because he represented himself after the paralegal filed a claim.
The lawyer didn't normally practice litigation, so he didn't use a cover sheet that would have limited his potential damages. There are plenty of people, including lawyers and civilians, who think they could do a better job — or at least a less expensive one — than a real lawyer.
In a criminal case, you have a Sixth Amendment right to self-representation, but that right is not absolute. A judge can deny a request to defend oneself if the defendant doesn't have the mental capacity to do so, and the judge can put a stop to the self-representation once the trial starts if the defendant is disruptive.
In any case, not having a lawyer with expertise in the area can prove more costly than the fees of hiring one, as the $100,000 mistake lawyer (as he likes to be known) can tell you.