Physical therapists who continue treatment after they have been directed to stop by the patient can face liability. However, no experienced medical malpractice attorney can give you a yes or no "is this malpractice" answer based on an online summary posting, even on a great legal site like AVVO.
The short summary answer is that the medical malpractice law comes right out and states that medical malpractice requires more than simply an unfortunate medical result. Professional medical liability is based on proof that the care that was given fell below the average standard of care, and that damages resulted as a result of that substandard care.
A determination is more a medical decision than a legal determination and malpractice attorneys work with medical experts to screen the facts and records in any given case prior to determining if any case merits going forward.
If you believe that there may be a case, please make an appointment with an experienced medical malpractice attorney in your jurisdiction for a confidential and no cost initial consultation.
I truly wish you the best.
This answer is provided for informational purposes only. Actual legal advice can only be provided in an office consultation by an attorney licensed in your jurisdiction, with experience in the area of law in which your concern lies.
I would strongly agree with Mr. Myers about seeing a medical malpractice attorney. Be sure that the attorney does handle that type of case as it is rather specialized, especially in California. ( I do not handle such cases).
However, the most important thing for you and your wife to do is get a medical evaluation of her current status and start treatment, with a different therapist.