The Marceau family believe the decision by Judge David McNaughton to release Akshay Chand on bail last October sealed Christie's fate.
Releasing Chand allowed him to carry out the plan he hatched in custody to stab Christie to death.
But a legal expert says the judge made a careful and considered decision and "had no other option" other than to release the 18-year-old.
Professor Warren Brookbanks, a University of Auckland specialist in criminal and mental health law, explained to the Herald how the bail process works and the specifics around the Chand decision.
Judge McNaughton was not available to talk about the issue and Chief District Court Judge Jan-Marie Doogue would not speak to the Herald.