I had sued my business partner for fraud, he has retained an attorney to represent him in the lawsuit. I have spoken to his attorney on the telephone about another business matter I had in the past but I never retained him. Is this considered conflict of interest?
Personal Injury Lawyer
Probably not. If you are concerned about it, raise the issue to him in writing and request a written response. That may be enough for him to withdraw from the case.
Conflicts of interest are regulated by the Rules of Professional Conduct. Rule 1.8 is the general rule. It does not appear from your description that would be a conflict, since you said that what you spoke to the lawyer about was a matter unrelated to the suit that you have now brought.
You can read the RPC provisions at: http://www.courts.wa.gov/court_rules/?fa=court_rules.list&group=ga&set=rpc