Hundreds? I'd really question that number.
Why are they not given compensation, for that matter? If you die in the military, your family gets the standard (whatever that is) no matter how you died pretty much, right? I suppose if they were proven to be maliciously fucking around or something that might be different, but in general, you die in the line of duty, it doesn't have some caveat about it not counting if a UFO does it, right? That seems to be what you're saying, so I'd need to see proof of that.
I'd need to see proof of any of that, honestly. You say it like it is common knowledge, yet somehow I doubt it is exactly as you are saying it. Unless your definition of "UFOs and related phenomena" and "no compensation" are different than mine.