The intimate visual recording offence came to light after the woman, who had been staying with Gwilliam for a few days, was using his laptop to access her Facebook page.
A further eight recordings of the woman were found on the laptop. Gwilliam told Judge Louis Bidois that he set up the video camera function on his laptop to record the woman because he suspected her of drug-related criminal activities.
He emphatically denied his intentions were sexually motivated saying he found the suggestion "abhorrent" and claimed the woman had tried to blackmail him when she confronted him.
He further claimed she was aware the video camera was on during some of the filming.
His lawyer Glenn Dixon said the intimate video recording of the woman taken through opaque glass was at the "lower end of the scale" and the victim's background and Gwilliam's medical problems were highly relevant considerations.
He said the consequences of the bomb blast had left Gwilliam suffering a post-traumatic stress disorder and a cognitive impairment that included him making some "very poor choices".
A stressed Gwilliam had self-medicated with drugs which he was no longer consuming.
Mr Dixon said community work and reparation were appropriate given the historic nature of the offences and the medical progress Gwilliam had made with the help of an occupational therapist.
Judge Bidois told Gwilliam recording a woman in the shower without her consent was a serious matter and clearly the recording had caused the victim "considerable distress".
Gwilliam was also ordered to pay $100 emotional harm to the man he assaulted and disqualified from driving for 12 months.
Gwilliam, nicknamed "Dave the Kiwi" at home and abroad, suffered serious head and shrapnel injuries in July 2007 while engaged in security contract work in Iraq.
The armoured vehicle he was in was struck by a blast from a remotely detonated bomb. The blast gouged a hole in Gwilliam's helmet and blew it off his head. His body was punctured by shrapnel and he had emergency surgery and was flown to England to recover.
In January 2009, he was awarded the Defence of Freedom medal for the injuries he suffered - the civilian equivalent of the US military Purple Heart awarded to personnel wounded in action. In March 2010, Gwilliam escaped a criminal conviction for cannabis cultivation after police found 12 cannabis plants at his home in November 2009.
