In February, David A. Dorfman won the 1999 Outstanding Young Lawyer Award from the New York State Bar Association in recognition for his volunteer work, an honor that seemingly marked the Manhattan attorney as a positive force in the legal community.

But this week Mr. Dorfman’s credentials were tarnished when a Manhattan federal judge refused to upset a jury’s finding that he had committed fraud and mishandled a client’s claim that a New York City laboratory had falsely diagnosed the man as HIV-positive.