Medium Transport; Low Wing; 2 Turbojet Eng
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 8
Confusion; Situational Awareness
Conflict NMAC; Deviation / Discrepancy - Procedural Clearance
Flight Crew Took Evasive Action
Procedure; Human Factors
Aircraft X was told to maintain visual separation from Aircraft Y.  Aircraft Y was told that Aircraft X would be maintaining visual separation as he descended through his altitude.  Aircraft Y later advised me that he was responding to a RA.  I advised Aircraft Y that; that was Aircraft X that was maintaining visual separation.  Once the aircraft passed each other; Aircraft Y questioned what happened and I asked Aircraft X if he heard Aircraft Y to which Aircraft X responded yes and stated that he was maintaining visual as he went around Aircraft Y. I reported the RA to my supervisor.  When I came into work; my supervisor; advised me that the event was now being processed as a near mid-air based on what Aircraft Y stated in a phone interview and proximity criteria.   I would not use visual separation.
Attempted a call back but the number given is a fax machine.
ZJX Controller reports of a situation where one was maintaining visual separation from the other. The one not maintaining visual; responds to an RA and later calls the facility and declares an NMAC.