Only for friendly-fire or self-inflicted wounds recieved in the HEAT OF BATTLE, not resulting from gross negligence. If you're pinned down by enemy fire and your grenade bounces off a tree and frags you, then maybe you can get a PH.
If you're not under enemy fire, as Kerry admitted in his journal, and you get some rice in your butt cheek from loitering too close to an exploding rice bin, that doesn't qualify.
I don't believe this is true. IIRC, wounds received in the course of destroying enemy assets do qualify. If the rice was a legitimate enemy military asset, then the wound would qualify for a Purple Heart, even if it is unintentionally self-inflicted, unless it is the result of negligence.
Given the unpredictable nature of war, I would imagine the definition of what constitutes negligence for 19-year-olds carrying around hand grenades on a daily basis is fairly narrow.
An interesting question would be whether or not a bin of rice can be considered a military asset.
Was Kerry acting under orders when he destroyed it, or was he just horsing around?
Did the US Military have a policy of denying the enemy food?
Was it clear that this food was meant for the enemy, or was John F'n committing a war crime by denying food to the general population?