Bogart-Mott told police he had called emergency services after Dunne had been unconscious for about 30 minutes.
A paramedic who arrived at 10pm that night says Bogart-Mott admitted to hitting Dunne's head on the brick wall several times.
Constable Bramwell Lancashire said Bogart-Mott also repeatedly stated "he hit me first". Bogart-Mott's older sister says he rang her for advice after the fight.
"He sounded panicked and said, 'I got into a fight over the money'. The guy that he got into the fight had been passed out for around 30 minutes and he didn't know what to do," she said in her police statement.
She says her brother did not want the police to get involved, but she told him to call an ambulance.
"I sent him a message that said, 'Well, go to jail for murder instead then, you idiot'," she said.
Dunne was taken to hospital for emergency surgery but died after his life support was switched off.
The committal hearing to determine whether Bogart-Mott should stand trial for murder will resume on Friday.