What is the test for a motion to disqualify an expert witness in a civil matter?

The court's power to disqualify counsel derives from its inherent power to control the conduct of its ministerial officers. (Code Civ. Proc., 128, subd. (a)(5); Roush v. Seagate Technology (2007) 150 Cal.App.4th 210, 218.) Disqualification motions implicate important interests of preservation of public trust in the administration of justice, a client's right to counsel of choice, the attorney's interest in representing a client, the financial burden of replacing a disqualified attorney, and any tactical abuse that may underlie the motion. (Id. at pp. 218-219.) Disqualification is a drastic action that should not be taken simply from hypersensitivity to ethical nuances or the appearance of impropriety. (Id. at p. 219.)

In disqualification of expert witness cases, the party seeking disqualification bears the burden of establishing that the expert possesses confidential information materially related to the proceedings. (Roush v. Seagate Technology, supra, 150 Cal.App.4th 210, 220.) Although the moving party is not required to disclose the actual information contended to be confidential, he must set forth the nature of the information and its relevance to the proceeding. (Ibid.) Once this showing is made, a rebuttable presumption arises that the information has been used or disclosed in the current employment. (Ibid.)

Page 6

The trial court's decision denying a motion for disqualification is reviewed for abuse of discretion. (Roush v. Seagate Technology, supra, 150 Cal.App.4th 210, 218.) "'[A] disqualification motion involves concerns that justify careful review of the trial court's exercise of discretion.'" (Ibid.)