Hunters pet able to attack while hunter was on mount

[Poe 0]

https://imgur.com/a/g6ESY

I know it's a bit difficult to tell, but the ?? hunter named "Khaz" was sending his pet to attack my group while he was on mount. He didn't leave mount at all during combat but his pet was able to attack multiple members of my raid group doing world PvP in southshore. 

As far as I'm aware this is not an ability that is available in Vanilla WoW.