While, generally, patent law depends on Federal Law, and provides federal question jurisdiction in Federal District Court for patent legal malpractice cases, here is an interesting state court appellate decision from Colorado.  Bristol v. Osman, Court of Appeals, Colorado.  It involves patent laches, and the statute of limiations in legal malpractice.  It also involves 6 amended complaints, the last four of which were submitted in contravention of the rules, and without any motion seeking leave.