The farm was placed on the market for $20 million nine and a-half years ago, but failed to sell, and went into receivership in March 2007, owing up to $30 million.
Subject to Overseas Investment Office approval, it is to be sold to the multibillion-dollar Harvard University endowment fund for about $28 million.
The relationship between Messrs Carr and Humphries has been labelled in various courts as acrimonious, and "dysfunctional".
The Patearoa farm was initially proposed in early 2001 as a "super farm", running up to 6000 cows on 1600ha using supplementary feed, which prompted widespread criticism at the time.
In recent times it had been running 3000 cows on about 1300ha. The Big Sky dairy syndicate formed in 2001 included Dunedin businessman Howard Paterson, who died in July 2003, Mr Humphries, and Mr Carr.
The latter has run the Patearoa farm since 1992.
When it was was placed in receivership the $30 million it owed included about $17 million to the BNZ.
In May 2009, Mr Carr was granted an application through the High Court to have Big Sky Dairy Farms Ltd and Cascade Capital Ltd placed in the hands of the Official Assignee for liquidation.
The judge said at the time the longstanding animosity between Messrs Carr and Humphries has "inarguably rendered the governance of the Big Sky Group of [six] companies dysfunctional".
Mr Carr had a one-third interest and Mr Humphries a two-thirds interest in each of Consultants Management Services Ltd, Big Sky Dairy Farms Ltd, Cascade Capital Ltd, Main Farm Ltd, and Tercio Dairy Ltd, collectively the Big Sky Group.
Justice Dobson said of "particular concern" were "substantial advances" and accrued interest by Mr Humphries of $9 million, advanced through his company Edgeware Motel Ltd to the Big Sky Group.
The receivers have deemed the $9 million a valid security and Mr Humphries a secured creditor, but this was disputed by Mr Carr, who claimed the $9 million security was invalid and therefore should be treated as an unsecured debt.
Estimates during the receivership in August 2007 were that several companies associated with the farm owed more than $30 million to a host of creditors.
Receivers at the time anticipated preferential creditors would be paid in full, including the BNZ, which forced the receivership and was owed $17.33 million, but payment for unsecured creditors, owed a total of $12.52 million, was dependent on the value of assets sold.
In June 2007, a potential settlement fell through because Mr Carr and Mr Humphries were thought to have disagreed about the value, although other sources understood Fonterra's increased forecast payout for milk solids was at the heart of the matter.
In mid-March this year, Mr Carr brought bankruptcy proceedings against his former business partner, Mr Humphries, over claims of a $238,000 debt.
They were settled on confidential terms in the High Court at Dunedin.
In July 2009, Messrs Carr and Humphries had separate bankruptcy proceedings lodged against them over historic debts totalling almost $560,000 for farm machinery, by the Otago Trustee Company Ltd, which administers the estate of Mr Paterson, who died in Fiji in July 2003.
The settlement was confidential.
In May 2009, in the Dunedin District Court, Mr Humphries was discharged without conviction on a charge relating to the theft of a Mowzip flail mower, the property of Mr Carr, in September 2007.
Mr Humphries was ordered to return the mower and to pay $500 court costs.
In April 2009, tenders closed for the sale of the 147-year-old Danseys Pass Coach Inn near Naseby, after the hotel owner, Anesyds Ltd, whose directors were listed by the Companies Office as Mr Carr and Mr Humphries, was placed in receivership in March 2007.
At the time it went into receivership, the company owed about $1 million to Edgewater Motel Ltd, owned by Mr Humphries.
In early 2003, the dairying venture appeared to have soured after Mr Paterson's A2 Corporation filed a winding-up application in the High Court against Big Sky over a $75,000 debt, but the matter was settled out of court, after the filing was reported.
