Judicial Conflict in Death Case?

A federal judge who dealt with some issues in the Ross execution in Connecticut had filed a motion in the case as a lawyer. In 1992, U.S. District Judge Robert Chatigny filed a motion on behalf of a bar association to file an amicus brief.  My sense is that this does not raise a conflict of interest, although the judge's critics believe it does.  Comments open on this.  [Jack Chin]