- Because of the specialized skill and training needed to be a doctor, lawyer, accountant,
- architect, or engineer, courts defer to the expertise of the profession to determine the
- appropriate standard of care.
In the professional negligence context, custom plays a different role than it does in typical negligence cases. In professional negligence the defendant's compliance with the custom of the profession is determinative, it insulates the defendant from negligence liability. Custom, then, establishes the standard of care.
- In addition, because of the complexity of the issues involved, expert witnesses are usually
- necessary for the plaintiff to establish the standard of care and to help determine if the
- defendant deviated from that standard.