My guess is that he (or one of his guests) was shooting at birds for “fun.” Naturally, he played stupid when you queried him about it.
It’s quite possible that they are shooting “short” of the backstop and the bullets are ricocheting back into the air.
Very common problem with unwitting shooters.
I don’t know, I just thought it was interesting that the bullet could travel in such a weird way. Anyone know how to do a screen shot for Google Earth?