I know this post should be in the hunter bug discussion topic, but lets face it the discussion there is pretty much dead and I wanted to shed some light on this bug. Currently we can not use some of our abilities under deterrence while we should be (for example master's call). There was another bug report on this already but it was wrongfully marked as fixed. (http://bugtracker.warmane.com/issues/9197)
"Deterrence is a hunter ability learned at level 78. For five seconds it enables the hunter to escape melee, ranged, and spell damage and also reduces damage taken by 30%. While unable to attack, the hunter can use traps, non-damaging abilities, command their pet, and also use [Kill Command].2
Source -> http://www.wowwiki.com/Deterrence
So please go bump this bugtracker post so it could get fixed some day.
http://bugtracker.warmane.com/issues/9326