Many times I have thrown a Tripmine grenade for it to blow up in my face if I'm too close to an enemy or for an enemy to shoot it then kill me. Just now I was doing the Nexus strike mission for my exotic bounty. I threw a Tripmine at the nexus boss thing, he shot it and I died. I was also doing the complete a strike without dying and get 9000 experience without dying (only about 1000 experience left) so I had do that all over again. Its a total balls ache and I think that grenades shouldn't be able to kill you in PvE because of charging enemies.
[b]UPDATE:[/b] they at least shouldnt be able to kill you. Maybe damage you quite a bit so that your vilnerable but not kill. And I don't mean the enemy is infront of me then I throw it, I mean when enemies are far away then they start charging/suddenly teleport infront of me....
I clicked thinking this would be some troll attempt. But alas OP is just salty. Of course they should damage you. I understand being mad about getting boned by the AI, it's happened to all of us at some point.
Also props to the OP for actually doing his strikes and not AFKing the bounty .