Derek M. Mah

“When I was a physiotherapist, I was able to help people and make a real difference in their lives. Now, I help injured people through the legal process and continue to make a real difference in their lives. This opportunity is very rewarding.”

Derek M. Mah

Derek M. Mah

Associate Counsel, Harper Grey LLP 604.895.2840 Derek Mah Law Corporation Download VCard LinkedIn Download PDF

Kristen Koo

Assistant 604.687.0411 (Ext. 2178)


Derek is Associate Counsel with Harper Grey’s Critical Injury Group. Throughout his career, as a physiotherapist and a lawyer, Derek’s focus has been on helping people who have been hurt.

Having graduated from UBC with a Bachelor of Science degree in Physical Therapy, Derek practiced physiotherapy at the Richmond Hospital and at private clinics until 2003.

“I enjoyed my time as a physiotherapist. When I decided to pursue a career in law, I understood that my knowledge and experience in health care were an advantage to help injured people untangle the legal challenges.  But, just as important, knowing the rehabilitation and medical challenges that my clients faced meant that I was able to support them better.”

While still practicing as a physiotherapist, Derek returned to UBC to obtain his LL.B. and was called to the B.C. Bar in 2004.

Following his call, Derek worked at a large downtown firm and specialized in the defence of ICBC and other personal injury claims. In 2006, he began to represent only people who have been hurt in accidents including ICBC car accident claims and slip and falls.

“Defending personal injury claims provided me with good insight about how insurance companies and defence lawyers operated. I was thankful to work with some good people but I knew my passion was to help injured people.”

Derek’s training and experience as a physiotherapist and defense lawyer provides him with unique insight into the medical and legal issues that his clients face. He also acts for the Public Guardian and Trustee of British Columbia on behalf of children who are unable to care for themselves.  He has appeared as lead counsel in the British Columbia Provincial Court, Supreme Court, and Court of Appeal.

Derek was born in Vancouver and raised in Richmond. Through high school, he worked in the family printing business and in the summers, at a fish cannery. In 1992, he graduated from St. George’s School and then, went to UBC and graduated with a Bachelor of Arts degree.

Derek lives in Vancouver with his wife and two children. He coaches youth soccer, hockey, and baseball and enjoys painting. His most well-known piece is the 1994 Canuckmobile.


  • University of British Columbia, LL.B., 2003
  • University of British Columbia, B. Sc. (P.T.), 1999
  • University of British Columbia, B.A., 1996

Bar Admission

  • British Columbia, 2004


  • Member, Trial Lawyers’ Association of British Columbia since 2010
  • Consultant, UBC Law Students’ Legal Advice Program since 2011
  • Board Member, St. George’s Old Boys Association Board since 2014
  • Board Member, UBC Institute of Mental Health Advisory Board since 2015

Rankings & Recognitions

  • Recognized as a “Leading Lawyer” in the area of Personal Injury Litigation  by Best Lawyers® in Canada, 2018 – 2019


  • Judge, UBC Law School Moot Court since 2009
  • Presenter, Trial Lawyers Association of British Columbia – Pleadings, December 2015
  • Presenter, LifeMark – Charting, Interviews, Medical Legal Reports and Testifying, January 2015
  • Presenter, UBC Physiotherapy Graduating Class – Charting, Interviews, Medical Legal Reports and Testifying, August 2014
  • Presenter, Trial Lawyers Association of British Columbia – Young Lawyers, February 2014
  • Presenter, Physiotherapy Foundation of Canada – Injury Law Update, February 2014
  • Presenter, Richmond Hospital – Informed Consent, November 2010
  • Presenter, Physiotherapy Association of British Columbia – Annual General Meeting, April 2010
  • Presenter, Continuing Legal Education – Personal Injury Conference, June 2009
  • Presenter, Continuing Legal Education – Personal Injury & ICBC Cases in Provincial Court, November 2008
  • Presenter, UBC Continuing Studies – Rehab and the Law, April 2007


  • Physiotherapy Association of British Columbia – Article Re: Swirski Interviews, June 2012
  • Physiotherapy Association of British Columbia – Article Re: Expert v. Lay Witnesses, September 2012

Recent Cases/Results

  • Assisting a young man who was told by ICBC that he was entirely at fault for a car accident. The Court found that the other driver was 100% responsible. ICBC appealed and was unsuccessful.
  • Helping a woman who has injured in a car accident recover $357,000 in compensation despite ICBC’s argument that most of her injuries were due to health problems that existed prior to the accident.
  • Recovering compensation for two young men who were injured in a “low velocity impact” or LVI accident. ICBC argued that people cannot be injured in a low velocity impact.
  • Helping a senior citizen recover $115,000 in compensation for an injury suffered when the bus driver pulled away before she had a chance to sit.
  • Helping a family recover compensation following a tragic accident when a high speed police cruiser ran a red light killing their husband/son.
  • Assisting a young woman who suffered a significant knee injury after stepping into a hole while playing softball. The defence argued that her claim be dismissed because she had signed a team roster which was also a waiver.
  • Helping a young man recover more than $340,000 in compensation when he suffered a broken leg after a car jumped the curb and pinned him against a wall. The defence appealed and was unsuccessful.
  • Assisting a woman recover compensation for injuries sustained in a slip and fall at a community centre. An application on behalf of the municipality to have the claim dismissed because she did not provide proper notice was unsuccessful. The defence appealed and was unsuccessful.
  • Helping a woman recover compensation for shoulder injuries she sustained in a car accident.
  • Assisting a young woman recover $550,000 for a disc herniation she suffered in a car accident. The defence argued that her injuries were minimal.
  • Assisting a family who were told by ICBC that they had mispresented the principal driver when they purchased their car insurance and as such, would not be covered for their loss. The Court found that there was no misrepresentation of the principal driver.