I thought irony was when the opposite happens of what one would expect. Like a DUmmie sacrificing his life in combat for the country.
more or less -
example - a person is afraid to fly in airplanes, for he fears the one he is on will crash, so, he takes a long trip across the country in a car. And is killed when a small private plane falls out of the sky crushing the car he is in. He expected to avoid nasty airplane death, however his actions actually brought it about. That's irony.
In the case of a DUmmy, it would be that he accidentally sacrificed his life with honor because he screwed up while running away, and tripped over something that caused the enemy to die as well. Such as hitting an IED tripwire while the enemy was still planting the device.