Cheap Shot, Sap - why rogues can use them even without any weapon in MH?

Hello fellas,

today i was disapointed and dazed when was cheap shoted by rogue who was disarmed. Then i logged on my rogue and check what is going on. In 2 words. YOU CAN.
you can use sap and cheap shot without weapon in MH but you cant use kidney shot.
After all only 1 question was born in my head "Is it bug or not?"

I didnt play by rogue much so can someone explain about these situation.

PS: cheap shot, sap, kidney shot requires melee weapon

it does say "Requires Melee Weapon" .its probably a bug.