Opinion is limited and Opinion is rescinded. A law firm must avoid the present representation of a cause against a client of a law firm with which any present lawyer, law clerk, paralegal, secretary or other ancillary staff member was formerly associated, and which cause involves a subject matter which is the same as or substantially related to that handled by the former firm while such person was associated with that firm.

A "Chinese wall" or "cone of silence" is insufficient to avoid an appearance of impropriety and may not be used to avoid imputed disqualification if a lawyer in the firm would be disqualified, or to avoid disqualification if the firm is disqualified because of the prior employment of a non-lawyer employee. Because of the appearance of impropriety, no exception is made for governmental lawyers or law offices.