Survival Tactics + Unstable Affliction... Getting hit with full spell damage

Survival Tactics dispels and gives hunters 90% damage reduction. Yet fairly consistently, I’m getting hit with the full damage from the UA dispel.

Imgur

From what I understand, this is intended. https://www.wowhead.com/spell=202746/survival-tactics#comments:id=2544812

It’s never worked like this and it doesn’t always hit. If it was intended, I would always take damage when dispelling UA.