The inquiry into the death of Mr Walker, 19, who was shot during a bungled arrest in Yuendumu in 2019, was played a video on Tuesday of Constable Zachary Rolfe detaining a 14-year-old boy.
After running from police the boy, who was wanted for a breach of bail, had hidden in a wheelie bin.
Video from Const Rolfe's body-worn camera showed him approach the bin and when he saw the boy inside he slammed down the lid before pulling it to the ground.
During his third day of evidence, Superintendent Jody Nobbs agreed the action to slam down the lid was an "act of unnecessary cruelty", and the way the bin was thrown to the ground was "very violent".
The inquest was told an investigation into the incident was closed with a finding that there was no excessive use of force and that Const Rolfe received a commendation for using his body-worn video.
Supt Nobbs said he wasn't in a position to properly comment on the full factors considered during the investigation.
But he said "prima facie that doesn't look good".
"Alternate options were available in terms of engaging with the youth," he said.
"It's highly necessary in our mind ... to continue to articulate what we are doing and why we're doing it to ensure there's no miscommunication and the flow from that is potential injury.
"Based on the narrow lens that you've provided ... it certainly doesn't look to align with our training framework."
Supt Nobbs also agreed with counsel assisting the NT coroner that the way in which the youth was dealt with as he was taken into custody was "humiliating".
In other evidence on Tuesday, the inquest was told that Const Rolfe had been involved in a total of 46 use-of-force incidents over a three-year period.
It was also told that more senior officers had counselled him over his failure to activate his body-worn camera on occasions, including one incident where he turned it off as he began to pursue a suspect.
Acting Senior Sergeant Alistair Gall, who previously described Const Rolfe as someone who could "get the job done", said that comment was more in reference to his reliability.
"I had identified in Zach Rolfe that he was intelligent, he was a good communicator. If I asked Zach Rolfe to do something he would do it," Sen Sgt Gall said.
But he said had he known of all the use-of-force incidents and complaints against the officer, that would have impacted on the decisions to deploy him to the elite Immediate Response Team.
"If he was developing a reputation of using excessive force I would want to know about that," Sen Sgt Gall said.
"That would impact how he was used."
Cont Rolfe was a member of a four-man IRT sent to Yuendumu to arrest Mr Walker.
Following the shooting, he was charged with the murder of the Warlpiri man but was acquitted after a Supreme Court trial.
The inquest continues.
