While I am unable to currently link the logs I have also had this happen to me twice over the course of the 4 attempts it took our raid to down Titan 6.
Also sorry for the tangent, but while on the topic of Resilience. In TFB HM it doesn't cleanse the Corrosive Slime DoT, whereas in SM it did. Same with the Terror's scream, in SM it resists the damage but in HM I have only had it resist approximately 1 out of 10 instances of the scream damage. I have been unable to find anything that tells me whether this is intended or not.
I've found the same on my Shadow. I just assumed it was intended that Scream couldn't be resisted in HM to prevent Shadows from cheesing the mechanic. Ironically, it can now be reflected but still applies the debuff. I also noticed around 1.7 that Resilience wouldn't cleanse the Corrosive Slime like it previously had.
I haven't noticed the issue you outlined KBN but I haven't been tanking 55 Endgame on my Shadow since 2.0 hit. Guardian buffs ftw! :P