Some Mediation Participant Comments “Mr. Diffenderfer quickly grasps complex issues of law and fact and, importantly, is able to measure the personalities of the participants and move within them effortlessly to place everyone at ease.  Mr. Diffenderfer’s gift as a mediator is to engage the trust of both counsel and claimants, so that all sides are confident that their points of view are understood and evenly presented.”

“He brings the refreshing combination of hard work ethic, intelligence and honesty to the mediation process.” 

“I was really impressed with his workup leading up to the mediation and his mediation style.”

“He is adept at arriving at out-of –the box solutions in cases that have stalemated up to that point.”

“His style is welcoming and friendly, yet he maintains a level of professionalism that makes everyone comfortable with his negotiations.”

Civil Litigation Background   Bill’s civil litigation career began in 1982 with one of the largest law firms in Contra Costa County. Sixteen years later and after ten years in the firm’s partnership, he began work as an attorney for a national insurance company. He was thereafter selected to manage company legal offices in San Francisco, San Jose and (on an interim basis) New York City. He has successfully tried cases to juries in various Bay Area Counties and his legal work took him to California Courts from San Diego to Eureka, the California Court of Appeals and Federal District Court.  He has served as continuing education presenter on a variety of topics to attorneys, paralegals, medical practitioners and claims organizations. His previous legal work included matters involving:                                            

Personal Injury--Automobile, motorcycle, truck, bicycle and pedestrian accidents---- Premises Liability, dog bite-- Public Entity Liability----Product liability, food contamination, toxic exposure---Professional Liability including Medical Malpractice and claims for malpractice involving insurance agents and brokers, realtors, architects and engineers----Construction Defect----Real Estate----Defamation and Privacy ---False Imprisonment, Assault and Battery----Contract and Business Disputes---- Work and Construction Site Injuries---Property Damage including fire loss, flood, crop and timber loss--- Insurance including insurance bad faith claims.

Legal Experience

Jan 09-Present    WDRC    


2004-2008          Law Offices of William J. Diffenderfer    San Francisco/San Jose, CA 

                                       Managing Attorney, Insurance Staff Counsel

1999-2004          Law Offices of Donald J. DeShaw / Law Offices of Carol L. Ventura   Fairfield, CA    

                                       Attorney/Assistant Managing Attorney, Staff Counsel                                                                                                          

1982—1999       McNamara, Houston, Dodge, McClure & Ney    Walnut Creek/ Fairfield, CA

                                   Associate Attorney, Partner (1990-1999)


University of California, Santa Barbara B.A. (with Honors) 1979

University of Oregon J.D. 1982

Specialized mediation training (including 40 hour Rosenberg Mediation Course)

Professional Memberships/Affiliations

State Bar of California

US District Court (Northern and Eastern Districts of California)

Contra Costa, Solano County Bar Associations

Association for Dispute Resolution of Northern California Premium Member

Resolute Systems, LLC Northern California Mediation Panel

iweb analytics

William J. Diffenderfer—Information and Experience

Mediation Experience    Mediation participant in hundreds of claims and cases over 25 year civil litigation career.  Twenty one years’ experience as Mediator (first as adjunct to regular litigation work and full time since 2009) with several hundred Mediations and settlements. 

Court ADR panels since 1990 and current ADR panel member in Alameda, Contra Costa, Santa Clara, San Mateo, Sacramento, Solano and Yolo Counties. Day of Trial Settlement Mentor in Contra Costa County/SF Bar Association Early Settlement Program panelist.

Responding to calls in the legal community for affordable, efficient and effective resolution services.