Yo, discovered a bug when a priest uses MC on u when u have ur felhunter summoned.
So when u get MC u lose controll of ur pet, that is right. But when MC expires, it takes several seconds to regain control of ur felhuntet, making it impossible to kick priests follow up MC.
Happened to me in arena yersterday. Warlock should get controll of his pet instanly when MC expires