The judge outlined how an email was sent to the New Zealand Herald and the National Business Review which seemed to come from the then SFO chief executive Adam Feeley.
When the NBR brought the email to Mr Feeley's attention, forensic investigations were undertaken by PwC which revealed no such email was sent by Mr Feeley or came from the SFO.
"While there was not actual evidence to prove Ms Killeen forwarded the forged composite email, by the process of deduction it certainly appears it was sent by her to the press," the judge said.
"Ms Killeen's culpability was at the lowest possible level in respect of her offending."
This was because the prosecutor, who was up until the time of her arrest practising as a barrister, had undertaken a course of fertility medication which in 1 per cent of cases caused severe psychological side effects, Judge Sharp said.