Like a ♥♥♥♥♥ (die in cover)

[Ambiguous Assassin]

So I threw a grenade near the edge of a desk and took cover behind it. The grenade exploded, I blew up... and didn't get the achievement.
Why not? I was behind cover, after all.

[Owen]

Good catch. Never even thought of it like that. The achievement is tied to bullet death, not explosions. I'll fix it in the next patch.

[Ambiguous Assassin]

It's not fixed. I tried it today, and still didn't get the achievement.

Incidentally, it seems strange when you can attract the attention of an enemy (close enough to see you), duck into cover, and it walks right past you.