In malpractice cases where a law firm is accused of screwing up a lawsuit, does the unhappy client have the burden of proving that a judgment in the underlying case would have been collectable? Thirty jurisdictions have picked sides in this dispute.The majority rule — followed by 17 states, including Illinois — assigns this burden to the malpractice plaintiff. But based on the Restatement (Third) of the Law Governing Lawyers, a federal judge in Utah adopted the minority rule. Bella Monte Owners Association v …