There have been a number of well documented cases of long arm projectiles traveling significant distances (after hitting an object) and killing another person. The Brooklyn NY case where a .303 round bounced off water and hit a young woman in the head as she drove along a highway a mile or more away (Open windows in her car. Event witnessed by a following NYPD lieutenant).
I know of another case, this one in NJ, where some young men were shooting at turtles in a pond and one of their military weapon projectiles (another .30 caliber if I recall) bounced off water and killed a man working on his roof miles away.
But, bouncing off the head of a boar, doing a 90 degree turn, and then killing another man? I'd like to see the ballistic labs report on the spent round first.