One tweet has caused senior Ashley Patrick to lose what mattered most: the chance to walk across the graduation stage to receive her School of the Arts diploma.

The Charleston County School Board voted 4-1 Wednesday to uphold the North Charleston Constituent School Board's decision, which was allowing Patrick to stay at School of the Arts on strict probation. That means she can't go to the prom or participate in the school's graduation ceremony with her classmates, but she will get a diploma from School of the Arts.

Patrick was expressionless as she listened to the board's decision, and she walked out of the room in tears.

“(Walking with her class) was what she wanted, and that's the one thing they want to take away from her,” said Dwayne Green, her attorney.

The district administration asked the county school board to remove Patrick from School of the Arts and send her to Twilight, a computer-based alternative program for students who misbehave. The district staff didn't think a five-day suspension was enough punishment for Patrick's tweet about a black junior in one of her classes.

In February, Patrick was at home when she posted on Twitter that if the junior “makes one more got damn remark in Roger's class tomorrow ... (expletive) will drop.” Patrick posted a link to a picture of a young white girl squeezing her eyes shut and crossing her fingers. The text on the photo read “I wish a nigga would.”

The reason Patrick won't be able to go to the prom or graduation is because she is on strict probation, which includes no extracurricular activities. Those involved in the case disagreed about whether prom and graduation were considered extracurricular activities.

The county school board and the district administration said Wednesday that Patrick wouldn't be allowed to go to either, but North Charleston Constituent School Board Chairman James Perry Jr. said his board never intended for Patrick to miss those rites of passage. His board thought she should be able to attend those functions, he said.

Perry said Wednesday he would attempt to clear up the confusion.

“How we put it is as plain as the nose on your face,” Perry said. “We're going to get it cleared up.”

Green said he asked the county school board to clarify its ruling in writing and whether it intends to bar Patrick from graduation. He is waiting for that information before deciding how to proceed, he said. Patrick said she prefers not to comment until they receive clarification on that decision.

County school board member Todd Garrett said the board did what Patrick wanted and upheld the constituent school board's decision without giving any further punishment. Garrett said he understood the constituent board's strict probation to mean no prom or graduation, and Patrick didn't ask during the hearing that she be able to go those activities.

If the constituent school board intended for Patrick to be able to go to those events, then she should be allowed, because the county board simply upheld its decision, Garrett said.

Chairwoman Cindy Bohn Coats said the first question she asked during the hearing was what the county board was being requested to decide. The issue was where Patrick would finish her high school career, and Bohn Coats said graduation or prom weren't an option as long as Patrick was on probation.

No one questioned what “extracurricular activities” covered, and Patrick didn't ask that those be an option, she said.

“It's an unfortunate situation that (Patrick and Green) didn't know what it meant,” she said. “I am sympathetic to their confusion, but every player had the responsibility to do their due diligence prior to (today).”

County school board Vice Chairman Craig Ascue said Patrick had a lesson to learn, and this was part of it.

“There are worse things in life for a high school senior,” he said of Patrick's being unable to walk at graduation.

Board member Elizabeth Moffly was the lone vote against the majority, and she said Patrick had enough punishment and she didn't want to prevent her from attending graduation and prom.

“She got the book thrown at her,” Moffly said. “How many punishments can you give someone for one offense?”

Green has questioned whether Patrick was facing a stiffer penalty than others would because the black junior named in Patrick's tweet was the daughter of Lisa Herring, a high-ranking district leader.

The North Charleston board that backed Patrick is all black; two of the five county board members voting Wednesday are black.

The county board met with Patrick for more than two hours in a closed-door hearing before making its decision. Jay Bender, an attorney for the S.C. Press Association, said the subject of a hearing can ask that it be open, but the school district's attorney, John Emerson, countered that state law doesn't mention students when citing who can waive their rights to a private hearing.

The county school board also specified in its ruling where Patrick must do 20 hours of community service — at a readers program at Liberty Hill Academy — and that she write a 500-word paper on racism and social media.

Reach Diette Courrégé Casey at @Diette on Twitter or (843) 937-5546.