Heimdall Synergy Against the Grandmaster's SP1

Wedgemonster

While I'm at low health (below 30%) and taking a blocked or unblocked hit via prompts from the Grandmaster's SP1 (does no damage) it is frequently triggering Heimdall's life save. It seems it is registering the hits as if they were doing damage, which it should not. I then no longer have the advantage of his synergy at a time when I actually need it.