I think Woody55 is on the right track with the insurance angle. This is a nuisance suit. Some insurance companies are willing to pay a few thousand dollars early in litigation because it's cheaper than actually litigating the case to conclusion. Some are not. Yet, if there is no basis in fact to claim Leone negligently shot Cutrufelli, then it seems to me Cutrufelli's attorney can possibly have some liability, depending on state laws and the willingness to pursue the attorney.
Federal Rule of Civil Procedure 11 (and many state rules) allow sanctions against attorneys in certain circumstances. FRCP 11 states, in part:
(b) Representations to the Court. By presenting to the court a pleading, written motion, or other paper—whether by signing, filing, submitting, or later advocating it—an attorney or unrepresented party certifies that to the best of the person's knowledge, information, and belief, formed after an inquiry reasonable under the circumstances: . . .
(3) the factual contentions have evidentiary support or, if specifically so identified, will likely have evidentiary support after a reasonable opportunity for further investigation or discovery; . . .
(1) In General. If, after notice and a reasonable opportunity to respond, the court determines that Rule 11(b) has been violated, the court may impose an appropriate sanction on any attorney, law firm, or party that violated the rule or is responsible for the violation. Absent exceptional circumstances, a law firm must be held jointly responsible for a violation committed by its partner, associate, or employee. . . .
Most courts only begrudgingly enforce Rule 11 because they do not want to encourage a cottage industry of Rule 11 litigation. Yet, they sometimes do so. I do not know if California has a state counterpart to Federal Rule 11.