John responds, "Oh my back, my back."
An officer films him being sprayed with the hose and John can be heard in the footage saying: "You happy?... how tough are youse (sic)?"
The incident left him "humiliated and degraded" according to Robinson Gill Lawyers, which is representing him. He had not committed a crime and has not been charged, they said in a statement.
Fearing reprisal, he sought legal representation before making his complaint against police, the firm said.
The case is one of many showing the police complaints system is broken and requires an independent body to investigate police misconduct, it said.
"Many of our clients are left frustrated and disenfranchised by the police complaints system," the firm said in a statement.
"In many instances, clients who have submitted substantial evidence regarding allegations of egregious misconduct have had police determine their complaints as being unfounded or not substantiated.
"In our experience, the findings of police investigations do not correlate with the outcome of civil proceedings."
A statement by Victoria Police says it has no tolerance for poor behaviour within its ranks and will examine any new evidence carefully.
"We want people to have absolute confidence that when they make a complaint against police, it will be investigated thoroughly and with integrity," the force said.
- AAP