The mother of an RFS volunteer accused of lighting several bush and rubbish fires says she doesn't remember giving evidence to police because she was on medication that made her believe she was in the Wizard of Oz.
Joshua Bruce Staples, 20, is accused of lighting 10 fires around Bringelly, Badgery's Creek and Greendale in January 2011, while he was working for the RFS.
Mr Staples has pleaded not guilty to 10 charges. He no longer volunteers as a firefighter.
At a hearing in the Downing Centre Local Court on Wednesday, Mr Staples's mother, Jennifer Carter, read aloud from a statement she gave to police on January 20, 2011, the night of her son's arrest.
Mrs Carter told police that she, her husband and her son had access to the family's three cars, some of which the court has heard were linked to the scenes of the blazes by police surveillance.
She said in her statement the cars had empty petrol tanks, were parked on the family property, or driven by someone other than Mr Staples at the times of the fires.
But in court, Mrs Carter said she didn't remember giving the statement because she was on several medications at the time, including Stilnox sleeping tablets.
Mrs Carter also claimed to have been intimidated by police when she was interviewed.
"[I was told] if I didn't speak right then and there, I wouldn't see my son. My son would be locked up and the key would be thrown away," she said.
"I ... have a memory of someone walking in behind me, a big bloke. And looking at someone's socks thinking I was in the Wizard of Oz [because of] the stripy socks."
Under cross-examination from Mr Staples's barrister, Michael Coroneos, Mrs Carter said there were other people with access to the cars, including her brothers, family friends and friends of Mr Staples.
Police prosector, Sergeant Daniel McMahon, asked whether the new evidence about extra people having access to the cars was her way of trying to help her son avoid conviction.
"You're attempting to distance yourself from evidence you gave on the 20th of January?" Sergeant McMahon asked,
"No," Mrs Carter said.
"You're doing your best to assist your son in this case?"
"No, I'm not."
Mrs Carter said she was taking the prescribed Stilnox tablets in January 2011 and she would sometimes drive to friends' houses and have no memory of doing so later.
"[You were] taunted by the Wizard of Oz at the time. If these kind of delusions were moving through your head ... can you say that your memory of these people using your cars is accurate?" Sergeant McMahon asked.
"I can't say any of it ... I could have been driving at the time," Mrs Carter said.
The hearing before Magistrate Michelle Goodwin continues.