What is the test for disqualifying counsel in a personal injury case?

"The paramount concern [in determining whether to disqualify counsel] must be the preservation of public trust in the scrupulous administration of justice and the integrity of the bar." (In re Complex Asbestos Litigation (1991) 232 Cal.App.3d 572, 586.) "The important right to counsel of one's choice must yield to ethical considerations that affect the fundamental principles of our judicial process." (People v. SpeeDee Oil Change Systems, Inc. (1999) 20 Cal.4th 1135, 1145.)