Brenda Battle made an appointment with Gary Athman, a well-known divorce attorney. During the client interview, Brenda told Gary that she wanted a divorce and requested legal advice as to her rights. Gary informed her of her legal rights and counseled her on separate and community property. He also made recommendations on the steps she should take before beginning proceedings. Brenda did not retain Gary to handle her divorce proceedings but paid him for his time and his legal advice. Two weeks later, Sam Battle, Brenda's estranged husband, made an appointment with Gary. He asked Gary to begin divorce proceedings against Brenda.

a. Should Gary represent Sam against Brenda? If so, why? If not, why not?

b. What ethical rule or rules apply to this case?