A statement of account sent by a lawyer to his client is not "an accounting record of a lawyer".
A memorandum that advised as to the impact of income tax laws that was prepared jointly by an accounting firm and a law firm was protected by solicitor-client privilege since the law firm had accepted responsibility for this advice. Also protected was a legal memorandum which originally had been prepared by a law firm for a third party, but which later was sent to in-house counsel of the taxpayer (probably without the knowledge of the preparing law firm) for his comments.