"So did the judge do the right thing? By law, he did.
"Has the judge lost sleep over that? Has the judge questioned everything? Of course he has.
"It's just a terrible situation to be in."
Mr King said he supported parts of Christie's Law, the proposed amendments to the bail Act campaigned for by Christie's parents after her death in November last year.
Chand was found not guilty of murder on the grounds of insanity in the High Court at Auckland last week. He was remanded to the Mason Clinic as a special patient and will not be released until the Minister of Health deems him no longer a danger to the community or the Marceau family.
Christie had written to the judge pleading for Chand's bail to be rejected because she was worried he would take "revenge".
Chand wrote to the judge saying he wanted to apologise in a letter which he later admitted he concocted so he could be released to kill Christie.
Mr King said parts of Christie's Law were "sophisticated" and "thought-through" but he said a suggested risk assessment tool to judge judges was "costly gobbledegook".
He backed changes to the law that currently give a strong presumption of bail for those who are under 20, saying it would have made a difference in Christie's case.
Mr King said judges were not too lenient and needed their discretion protected from politics.
"As far as [the Marceau] case is concerned, though, let's not lose sight of the fact that the judge is forced to make numerous decisions in a day under pressure," Mr King told Q+A.
"The list called in the district court is like the A&E ward in a hospital: you've got people coming in, you've got multiple decisions. Maybe 100 different cases in a year, all of which involve judicial decisions having to be made on the hop."