A minority view from an anonymous physician:

There actually should be a law protecting expert witnesses from this type of abuse. Also, the theory that expert testimony constitutes medical practice is completely preposterous. The AMA and other physician groups should not be allowed to get away with it. I’ve tried speaking up about this at some medical meetings, but I now have given up. Most doctors are completely convinced that anything that one can do to make life harder for plaintiffs is to their benefit. I think that patients and patient advocates need to speak up and contact their representatives in Congress and the state legislatures or the AMA is going to get it’s way.