It's easy to say, but put clients (past and present) ahead of revenue to stay out of trouble.
In 2011, the GA State Bar changed Rule 1.7 Conflict of Interest. The changes require full disclosure of conflicts, and "informed consent" in writing and signed by current and former affected clients. When I originally wrote about the changes in my blog, I wondered if the enhanced Rule 1.7 would curb lawyers' attempts to enter into conflicting or potentially conflicting matters.