The punch a parent allegedly threw at a Castle High School assistant football coach Friday night after an emotional game has touched a deep chord of concern in Hawai'i student athletics.

High school athletic directors and an official in the organization that oversees high school athletics acknowledge that while this was an isolated incident, the high emotions surrounding sports events occasionally lead to abusive or dangerous actions.

"Every school is faced with similar problems," said Castle High athletic director Richard Haru. His office is investigating the incident that occurred on the football field about 10 minutes after the game Castle played against 'Aiea High on Friday.

The results of the investigation could lead to sanctions against the parent, who was arrested after the incident and is free pending investigation on possible charges of second-degree assault.

According to police, the suspect allegedly punched the coach because he was upset that his son did not play in the game. Police called it a "sucker punch" that the coach didn't see coming. The suspect was arrested at the scene and the coach suffered minor injuries.

"I think it's also safe to say it is a very isolated incident," said Haru. "We have hundreds and hundreds of student athletes and double that number of parents, and a very small percentage of incidents. But because it was such a profound incident it stands out."

Keith Amemiya, executive director of the Hawai'i High School Athletic Association, which governs high school athletics, said that while the incident Friday at Castle is rare, it shows that "some parents are out of control," even though most are well behaved.

Amemiya said the case is a reflection of what is happening in society as a whole, including the behavior of sports fans shown on TV.

"Some parents take sports and winning far too seriously," he said. "Some parents seem to be living through their kids when they should back off and let their kids compete for the fun and joy of it."

Amemiya's office doesn't keep a list of such incidents, but there have been several over the past few years, not just with unpleasant parents, but with unruly athletes. Several years ago a Baldwin High soccer player attacked an official, while two years ago a Konawaena High boys basketball player attacked a referee on the court, Amemiya said.

Amemiya said a number of football coaches have complained they've received anonymous phone threats and some coaches have even resigned because of pressures from unruly parents.

"Like in any situation, it's a few bad apples that ruin it for the rest of us," he said.

Joseph Whitford, athletic director at Kahuku High, is wrestling with just that type of incident in which a parent yelled at a coach.

As a result of a fairly contentious meeting between the coach and the parent, the coach may quit, he said yesterday.

"Coaches are taking the time to help these student athletes and it comes a point where they just don't want to deal with it," said Whitford.

"As much as they want to help the kids, the pressures from parents are sometimes too great. It's not worth it."

Clayton Fujie, deputy superintendent of the Department of Education, said high school sports can be an extremely high-stakes game for some parents who are counting on sports scholarships to help their children go on to higher education.

"It's the lure of college scholarships and what athletes are making in the professional ranks," said Fujie. He said that parents voicing concerns about how often their child is being played, or whether or not he or she should be cut from a team, have even landed on his desk.

Two years ago Fujie remembers being asked by a parent if his son, who was going to be suspended for a disciplinary violation, could serve his suspension after college scouts had visited the school.

"I just told the parents, 'I'm sorry, we're not the National Football League,' " said Fujie. "'The suspension starts now.'"

Castle's Haru, who also serves as the safety and security officer for the Oahu Interscholastic Association, said his school and others have to do "all they can" to try and prevent incidents such as the one that marred the post-game atmosphere Friday.

Haru said that before the football season even starts he brings parents together in a mandatory meeting to talk about the season, including how they and their children are expected to behave.

Amemiya, too, said HHSAA fans are warned before tournament games about their behavior. They risk being expelled from the game if they taunt, swear or wave offensive signs.

"We make it a practice to remind our fans to exhibit good sportsmanship," he said. "We've had to expel some on a few occasions, but none recently."

Reach Beverly Creamer at bcreamer@honoluluadvertiser.com.