And how does the last young women in the advert do harm to herself?
As for Max Cleland, he was hardly "playing with a grenade". As Max Cleland and another soldier were stepping off from a helicopter, a grenade fell into the underbrush. Cleland reached down to retrieve it, unaware that the pin had been pulled as it came off the other soldier's flak vest (all of that soldier's grenades had been improperly attached to his vest and anyone of them could have had the pin pulled at any time), and it went-off just as he grabbed it.

OCU