I think there’s a difference between you shooting strays on your property, a LEO just doing his job encountering a protective dog and a Dirty Harry wannabe going into a park and shooting what he thinks are evildoers.
You are on your property, shooting known strays protecting your livestock. The LEO is a shame but still an unfortunate accident. The Dirty Harry wannabe is a psycho who thinks he’s above the law.
There were options other than breaking the law available to this guy. He didn’t have to start shooting. Did he voice his concerns to the organization which ran the park? Did he explore a lawsuit to force the state to do something about it? No, he got the hankerin’ for killin’ and went off on his own.