Okay, so During the Baron Ashbury encounter in SFK Heroic. a Hunter (maybe rogue too haven't tested it) can avoid all of the damage from Asphyxiate Every time!
I accidentally discovered this from almost pulling aggro early on in the fight so i hit Feign Death, like a good hunter should. As i feigned he started to cast Asphyxiate, low and be hold i was stunned but not taking any damage because he thought i was dead!
I continued to hit Feign the second he started to channel Asphyxiate every time, and never took damage, Sometimes he even dropped me and i got to DPS more while all my friends were dying lol
When he starts casting it interrupts any casts you're doing and gives you a good .5 second window to hit Feign Death.
I know it's a relatively easy fight, but it's fun to be able to get the edge on other dps. similar to the Professor Putricide encounter, where mages and rogues could avoid that Stun.