Police are investigating Mr Hughes after an 18-year-old male student laid a complaint against him following a late-night drinking session, and Mr Goff yesterday stood him down and stripped him of his responsibilities.
But Mr Hughes told Mr Goff about the complaint after the alleged incident early on the morning of March 2, and for two weeks neither of them revealed anything about the inquiry.
That put Mr Goff in a difficult position yesterday, because in 2009 he attacked Prime Minister John Key for not revealing everything he knew about the sex scandal surrounding Richard Worth, a minister at the time who subsequently resigned from Parliament.
Mr Key stood down Dr Worth as soon as he found out about the allegations surrounding the MP, and yesterday Mr Goff had to admit he had been wrong when he demanded full disclosure.
"I think I've learnt one or two things about the complexity of these situations," Mr Goff said.
"I'm going to be the first to admit that I was wrong in the judgment that I made at that time."
He defended his decision not to go public about the complaint when he first became aware of it, saying he didn't want to prejudice the police inquiry.
The alleged incident happened at Labour deputy leader Annette King's Wellington home, where Mr Hughes boards, after he had been drinking at two bars with a group of students, including the complainant.
The student left the home and is reported to have either flagged down a police car or walked into its path.
It was then that he made the complaint.
Mr Hughes says he has done nothing wrong and is confident the legal processes will "lead to the right outcome".
Mr Goff's handling of the issue is being called into question, and it is a huge distraction as Labour readies itself to take on National at the November 26 general election.
Mr Goff yesterday said his caucus had not expressed any concerns and his leadership was not an issue.
Mr Key is staying out of it.
"In the end it'll be for the public to judge whether they think Mr Goff has handled the situation appropriately or not," he said.
