They circulated a photo of him and soon tracked him down, charging him with disorderly behaviour.
He pleaded guilty at Christchurch District Court two days after the incident.
Duty lawyer Steve Hembrow said at the time that Tuapawa was ashamed by his actions, saying he didn't have anything against Muslims.
He couldn't explain his behaviour and claims that he had blacked out.
Today, Judge Tony Couch said while it was a relatively minor offence, Tuapawa's conduct would've been distressing and offensive at any time. But given that it came less than a month after the mosque shootings, it "did make the situation much worse".
"Given the strength of public feeling about the murders which occurred there, your conduct could very well have provoked a violent reaction," Judge Couch said.
The court heard that Tuapawa has long-standing psychological issues and intellectual challenges.
Judge Couch said that Tuapawa had immediately accepted responsibility, despite not remembering what happened, and had taken initiative to get help and support "for issues that clearly affect you".
He sentenced Tuapawa to 10 months of supervision with a condition that he must attend any assessment, counselling or programme as directed by his probation officer.
The judge said he was confident that the sentence will be accepted by members of the Muslim community who "embrace forgiveness and compassion".