As a young person we had a rooster get tangled and hand upside down until dead in regular old chicken wire in the vertical sides of a run.
We lost two young birds last year to electronet when (we believe, did not see it) a hawk frightened them into the fence and they became entangled. But it works so very well most of the time that we are willing to accept the occassional loss to have the benefits. The birds are "trained" to the fence and do not even try to fly out as adults, although they very easily could. The elctronet allows us to move them to fresh pasture on a regular basis. Really cuts down the feed and bedding bills.
Sorry for your loss. We try so hard to protect our flocks, it hurts when the fence becomes the predator.