Waconia girls' basketball coach Carl Pierson said a recent Minnesota Supreme Court finding that he and fellow high school coaches are not public figures is a "game-changer'' that strengthens their hand when faced with accusations seeking to get them fired.

The court ruled Wednesday in a ground-breaking decision involving a former Woodbury girls' basketball coach that parents and others don't have legal protection to make false claims about high school coaches. It found that public high school coaches are not public officials under the First Amendment.

"Parents that deliberately defame or slander a coach can now be sued for tens of thousands of dollars,'' said Pierson, executive director of the Minnesota Girls Basketball Coaches Association. "This ruling will do more to protect coaches from malicious, baseless attacks than any level of legislation ever could."

Pierson called it "a monumental moment for coaches in Minnesota and perhaps beyond.''

Earlier in the week, the National Federation of State High School Associations said that "inappropriate adult behavior at high school athletic events throughout the country has reached epidemic proportion.'' Citing a national survey of more than 2,000 high school athletic directors, it said 62.3 percent of them said "dealing with aggressive parents and adult fans'' was what they liked least about their job.

The court ruling has no bearing on when such behavior questions coaches for decisions before or during a game, such as who starts or the wisdom of taking a timeout. Of significant note is when the behavior involves false accusations.

"Prior to this ruling, parents could impugn a coach's character with little fear of litigation,'' Pierson wrote in an e-mail to the Star Tribune. "After this ruling, a parent that makes false allegations in an effort to get a coach fired could be forced to pay the coach thousands of dollars in a defamation suit.''

Asked how big the problem was in Minnesota, Pierson said, "I don't know that I would characterize false allegations against coaches as pervasive, but they are not uncommon, either.''

He said the ruling "should act as a major deterrent to potentially pernicious parents.''

In 2013, Minnesota enacted a law stipulating that "parent complaints must not be the sole reason" for a school board to get rid of a coach. It was passed after high-profile boys' hockey coaches were ousted and amid pleas from coaches under growing pressure from demanding parents unhappy about playing time and team roles for their children.