Take a look at note 1 on page 401 for more examples of legal malpractice.
What happens when a lawyer drafts a deed conveying Blackacre to a son and his mother "as tenants by the entireties"?
Or to an unmarried romantic couple as "tenants by the entireties."
A court may--or may not--clean up the mess.
As Socrates said: “The only true wisdom is in knowing you know nothing."
Or, as I have been saying, lawyers need to know what they don't know. Either don't take on work that is beyond your legal expertise, or, if you take the work, make sure you learn what you need to know to do the work your client is entitled to receive.
