Kim Dotcom's reference to himself as "evil" was an intentional mistranslation by US prosecutors and the case against him is rotten, says the internet mogul's lawyer.
Mr Dotcom and three other men face extradition to the United States on charges of copyright violation, racketeering and money-laundering, related to their file-sharing website, Megaupload.
The hearing, under the jurisdiction of the North Shore District Court, is now in its seventh week.
However, several applications to pause or even stop the hearing altogether have meant the defence has only just opened its case this morning.
The Crown, on behalf of the US, claimed Megaupload made its money by aiding and encouraging copyright infringement on a mass scale.
Earlier in the case, the Crown lawyer Christine Gordon referred to Skype and email exchanges between the men that she said showed they knew what they were doing was illegal.
In one exchange, widely reported by media attending the extradition hearing, the Crown claimed Mr Dotcom said: "At some point a judge will be convinced about how evil we are and then we're in trouble."
What the Crown did not reveal in court was that the exchange was an FBI translation of the German original, Kim Dotcom's Ron Mansfield said.
When translated from German to English by three independent translators in New Zealand, the phrase was: "Because at some stage a judge will be talked into how bad we allegedly are and then it will be a mess".
That had quite a different tone and meaning, Mr Mansfield said.
However, Ms Gordon had repeated the first translation over and over again, knowing it would be widely reported, he said.
The summary of evidence contained other mistranslations and cherry-picked details, Mr Mansfield said.
"Where does the rot end?"
Mr Mansfield also told the court the Copyright Act provided protection from prosecution for internet service providers whose users broke the law.
Megaupload was created for a legitimate purpose, which was to share large files, Mr Mansfield said.
Simply providing that technology did not make the website responsible if users then put it to an illegal purpose, he said.
In an early stage of the hearing, Ms Gordon described Megaupload as a "simple scheme of fraud" that made money through encouraging people to upload copyrighted material.
However, the US indictment outlining the charges did not even mention fraud, Mr Mansfield said.
It was now retrospectively trying to "contort" copyright crimes - which Megaupload could not be prosecuted for - into crimes of fraud, he said.
The US Supreme Court had already ruled that copyright allegations could not be prosecuted as fraud or property and dishonesty offences. That meant that if Mr Dotcom was extradited, it would be on a basis that couldn't even be argued by the US at trial, Mr Mansfield said.
Internet giants such as Google were virtually immune from prosecution on copyright charges because of their huge resources, and the public outrage that would follow, Mr Mansfield said. Mr Dotcom's smaller business, and his "flamboyant and extravagant reputation", meant he was not so protected.
Extraditing Mr Dotcom would remove him from a country he now called home to a country he had never lived in and never run a business from, Mr Mansfield said.
"To say that this would have a significant impact on the respondent's life would be a gross understatement."