I got one shotted by Hans'gar and Franzok HC today multiple times, because I could not recognize when they actually do Crippling Suplex. The cast bar is showing up once they already grabbed you or the other tank. In case of the other tank, I can use Divine Protection or other defensive cooldowns, but both need to do that, before being grabbed.
I do use Deadly Boss Mods, but the warning there is unreliable and often too early, resulting in Divine Protection running out before I actually was hit by the damage. For what it is worth, I have ~440k Life buffed, a GS of 677 and I am a Protection Paladin.
This guide on icy-veins is inconclusive about that, unfortunately.