B737-800
Air Traffic Control Developmental
ATC Issue All Types; Conflict NMAC; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Human Factors; Procedure
Flight coordinated at FL350 southbound came over the boundary at FL360 head on with other traffic
Developmental Center Controller reported an aircraft came to them at the wrong altitude head on with another aircraft.