Unfortunately, it happens more often than what news media reports on.
Back in the late '70s, our family had a similar thing happen. Only it was done in daylight, just after sunrise.
Two guys from (Kansas City or Wichita, don't recall which) were "hunting" deer during deer season.
They were hunting in one of our pastures, w/o permission.
According to what they told the sheriff, in the distance they saw what they thought to be a very large buck. And one of them fired at it.
I point out that this "buck" was nearly 1/2 mile away!!!!
Long story shortened...the "buck" actually was one of our horses. A Palomino gelding worth a few thousand dollars.
My Dad & I had made a trip to Aurora, CO just 8 months before, to attend a high-dollar auction to buy him.
To this day, because of that, Dad doesn't allow hunting on his property...even though he himself @ 75 still hunts.