I remember a patch note from 1.02 or something:

"Hunters casting Eyes of the Beast while on a flight path will no longer be dropped to the ground at their current location"


And another...AFTER I'd done the quest in question:
"The debuff cast by Felhunters in Desolace that causes 300 damage to a player when they cast a spell no longer affects non-spell abilities from non-spellcasters such as a rogue using Sinister Strike"

I hated killing those stupid felhunters then...I could only white attack them...300 dmg was like 1/4 of my health at level 38 or so IIRC.