That created more delays leading up to an impending disputed facts hearing which in the end never went ahead, Symon said.
"In the Crown's submission, Mr Banbrook effectively adjourned the sentencing until it suited him ... Had the sentence proceeded in June, he would have been subjected to a sentence over the Christmas break."
He said Banbrook had shown little remorse and even asked for his passport back after pleading guilty so he could go on holiday to Fiji - something out-of-pocket investors would have found hard to swallow.
Symon said Banbrook was the only independent director because fellow directors Trevor Alan Ludlow and Carol Anne Braithwaite were in a relationship at the time.
He said had Banbrook taken the basic steps required of a director, he would have known the prospectus contained misleading passages. "Now he accepts he was grossly negligent."
Banbrook's lawyer, Harry Waalkens, QC, said the case had been delayed because his client did not accept the Crown's assertion that he knew about related-party loans, and it was significant the allegation had been withdrawn from the Crown's summary.
He said Banbrook had no intention of delaying the proceedings and only wanted his passport back so he could visit his son in Sydney.
Waalkens also said he had not been dismissed by Banbrook but withdrew because the week-long disputed facts hearing would have cost too much. "This is not a dishonest man, this is a man who has been caught up in the dreadful finance company collapses."
He said Banbrook now faced disciplinary action from the Law Society.
In sentencing, Justice David Collins said Banbrook had neglected to question other directors about the reliability of statements in the National Finance prospectus sent to investors. Justice Collins had started with a prison sentence but took time off to reflect Banbrook's previous good record, his remorse and his reparation payment.
National Finance went into receivership in 2006 owing investors $21 million. Some investors have recovered 49c in the dollar.
Ludlow is serving six years and four months in jail after a case brought by the Serious Fraud Office and the Financial Markets Authority. He was found guilty of defrauding investors of an estimated $3.5 million. Braithwaite was found guilty of making untrue statements in a prospectus and given home detention.