Those abilities only work on stunned Strong or Weak mobs.
They do not work on elites, champions and players.
your the closet to quoting the Tooltip for the ability....
its says and i quote
"" Slams into the Target with a Rocket-Propelled shoulder charge, dealing 3502 - 3535 Kinetic damage to weak or standard targets and 2517 - 2549 knetic damage to Strong targets, only works on incapacitated targets""
(no where in the tool tip does it say non-boss, non-champion, non-player, Now having said that i kinda got that impression when i tried to use it.. however as i said in the OP. my Assassin can use his Mirror Ability in pvp.
that was how my question was posed. why can assassins use theirs...and Bounty Hunters cannot. cause i mean thats a rocket punch.. it normally crits for 5-6k dmg. for me.