A Sydney police officer who tasered Brazilian student Roberto Laudisio Curti at the same time as another officer has denied he was so 'out of control' he couldn't hear the young man's screams for help.
Leading Senior Constable Scott Edmondson told the Sydney inquest into the death of Mr Curti on Thursday that he originally believed he was the first officer to taser the 21-year-old man as he lay on the ground surrounded by officers on March 18 this year.
Mr Curti died at the scene after several police attempted to restrain him by discharging their Tasers a total of 14 times and using capsicum spray, handcuffs and batons.
The inquest heard Lead Sen Const Edmondson, then a senior constable, was accidentally tasered by another officer as they pursued Mr Curti through Sydney CBD.
When he eventually caught up, he told the court Mr Curti was lying on the ground surrounded by about six police officers.
He said Mr Curti was 'resisting' police and was nearly throwing them off, so he applied his Taser directly to Mr Curti's bare lower back, or 'drive-stunned' him twice.
'It didn't have any effect at all,' Sen Const Edmondson said.
However, towards the end of his second drive-stun, Sen Const Edmondson said he noticed Probationary Constable Daniel Barling drive-stunning Mr Curti at the same time.
The inquest has heard evidence Prob Const Barling drive-stunned Mr Curti five times for periods of 7, 5, 14, 8 and 7 seconds respectively, but Lead Sen Const Edmondson said he only saw Prob Const Barling drive-stun Mr Curti once.
'That's just something you didn't see or hear or become aware of Roberto's screaming when it happened, you were just oblivious to that?' Peter Hamill, SC, representing Mr Curti's family, said.
Lead Sen Const Edmondson said he heard Mr Curti saying, 'aah', prompting Mr Hamill to replay the video footage of Mr Curti's last moments.
'At about the same time your colleague tasers Roberto when he's on the ground five times, in a period where you've tasered him when he's on the ground twice, Roberto coincidentally or otherwise screams in agony,' Mr Hamill said.
Mr Hamill later withdrew the phrase, 'screaming in agony', but asked Lead Sen Const Edmondson, 'You ask us to believe you didn't hear that?'
'I'm just telling you what I remember,' Lead Sen Const Edmondson replied.
Mr Hamill suggested Lead Sen Const Edmondson didn't think through any other options when he first came across Mr Curti.
'You had been zapped with a Taser and you decided to zap him with a Taser,' Mr Hamill said.
'You were so out of control you didn't hear five drive-stuns by Probationary Constable Barling where Roberto was screaming for help,' Mr Hamill said.
'I disagree,' Sen Const Edmondson said.
The court heard Lead Sen Const Edmondson began to regularly check Mr Curti's pulse once he had quietened down, but he did not move him into the recovery position, despite being aware of the dangers of positional asphyxia.
'This was one of the biggest wrestles I had ever been involved in,' he said.
'I don't want to move him into another position.'
Mr Curti's sister, Ana Laudisio, left the court in tears during Lead Sen Const Edmondson's evidence.
Earlier, Constable Annalese Ryan told the inquest the incident involving Mr Curti was 'loud, violent, scary'.
'He was definitely violently resisting us,' Const Ryan said.
The inquest continues before NSW State Coroner Mary Jerram.