The Spirit Resilience and Bullet Resilience items don't seem to be applying the extra 22% resists when under 40% hp.
Tested in a custom game/Sandbox and tried it on a variety of heroes.
Edit: My mistake, not a bug
Haven't tested before and haven't tested in a live game.
However, in Sandbox, performing a Heavy Melee on a bot after parrying seems to be doing less damage than hitting them without parrying.
Not sure if this is a bug but thought I'd report it. Have attached a video showing this.