The Boston Licensing Board decides Thursday whether to punish Pho So 1, 223 Adams St., for repeatedly staying open past its 10 p.m. closing time.

The board today heard details of police citations for incidents on Aug. 29 and Sept. 2. That's in addition to a similar incident in May and yet another incident on Sept. 16.

On Aug. 29, detectives found the restaurant still occupied at 12:10 a.m., karaoke going and patrons enjoying fresh bottles of beer. On a return visit on Sept. 2., Sgt. Det. Robert Mulvey said at a hearing Tuesday, detectives found the same situation, only this time, they had to call on help from uniformed C-11 officers when a belligerent patron not only refused to leave but began to argue with the detectives.

Mulvey added that in addition to staying open past its legal closing time, the restaurant did not have a license for the karaoke - yes, of course, karaoke requires a license in Boston.

The restaurant's lawyer, Marco Beatrice, told the board it's all an unfortunate cultural misunderstanding between Vietnamese friendship and family customs and Boston licensing requirements - to which the restaurant, he acknowledged had agreed.

In Vietnam, restaurant owners and workers and their families all partake of after-hours relaxation at each other's restaurants, Beatrice said. Owner Hoang Anh Nguyen, whose English is not the best, just didn't understand you couldn't lock the doors, turn off the signs and let family and friends enjoy themselves after closing time, Beatrice said.

"They're not paying customers for the most part," he said.

Still, he said he had impressed the importance of complying with local licensing requirements - including the closing time Nguyen had agreed to - and that Nguyen will not do that again, even at the risk of offending family members and friends. He added that the restaurant has had no other types of violations, has been named the best pho place in Boston by the Globe and has a petition signed by 20 neighboring businesses in support.

Board Chairwoman Christine Pulgini said she appreciated the lawyer's defense, but said the restaurant's repeatedly being caught open way too late "is not good; that's not good at all."

Mulvey said he was getting fed up with the violations as well. He said that during the Sept. 2 incident, the belligerent customer hurled insults - in English - that he said he didn't want to repeat, and that once he started in with the insults, Nguyen grew increasingly belligerent as well. He added that he and a fellow licensing detective normally don't have to seek help from uniformed officers to shut down a restaurant in violation of its license.

The board could find no violation, issue a warning or suspend the restaurant's license for a set number of days.