Just went back to using the Grinder perk for the time being, it doesn't seem to occur when you do something like... hit a mine at low health, or blow yourself up in the middle of explosive containers... but large groups with perma-hate make it temporarily useless it seems.
I can confirm this, just got the perk and first time it was used I got locked in the getting up animation only to be knocked down again while the mobs kept hitting me.
I am an Eternal Warrior though, I won't die, just have to spend eternity laying on the floor...:)
The Eternal Warrior perk seems to glitch when it activates more often than not while continuing to take damage ( happens a lot with sustained damage from flamers ) You never seem to actually resurrect, even though you can continue to use your Innoculator you can't move, nor use any other ability. I attempted to add a screen capture, though it appears to have locked me out of my original post above. I have tested this out to 10 minutes of just sitting in one spot continuing to take damage from various sources. The only way to end it, is to Surrender and end the playthrough.