Can an expert be examined as an expert in a medical malpractice action?

In Lawless v. Calaway, 24 Cal.2d 81, 147 P.2d 604, 609, the judgment granting a nonsuit was reversed solely because the court below was held to have committed prejudicial error in limiting the scope of the examination of defendant who was called as an adverse witness under the provisions of section 2055 of the Code of Civil Procedure. It was held in that case, a malpractice action, that appellant should have been [140 Cal.App.2d 763] allowed to examine defendant doctor as an expert in regard to the standard of skill and care exercised by doctors in that community. The court stated that an offer of proof was unnecessary where the court had declared an entire class of evidence inadmissible, and noted further that 'examination of a party under section 2055 is often exploratory and it would be unreasonable to require an offer of proof under such circumstances.' The court disapproved certain cases suggesting a different rule.