Russell, in her late 70s today, first engaged Herzog's services in 2008 for a High Court dispute with a member of her family.
She confided her stress in Herzog, according to Judge Sargisson's decision, and a close friendship developed between the pair. They swapped emails and texts and occasionally met face-to-face.
Herzog - who has previously represented high profile clients including Andrew Krukziener - describes the relationship as "mutually affectionate, supportive and caring", but makes no explicit mention (nor any denials) of any sexual aspect to their relationship, according to the judgment.
Russell characterises it differently: Herzog was flattering and she soon became "mesmerised" by him.
Her account is that the relationship quickly became sexual — indeed that Herzog "offered to have sex with [her]" immediately after settling the bill for his services in the family dispute.
From very early on there was also a financial aspect to their relationship beyond that of lawyer/client, the judgment says.
During 2009 and 2010 period, Russell made several unsecured advances to Herzog totalling $410,000.
Herzog says he was investing the money on Russell's behalf. Russell says the lawyer wanted it for his own purposes.
After Russell's accountant expressed concerns, Herzog agreed to sign a document describing the money as a loan, which he eventually repaid.
Herzog and Russell's relationship became more complicated in 2014, when Russell agreed to sell her Pukekoe properties to her niece and her husband, Jessica and Richard Kirkwood, for $4m.
Herzog advised Russell that the price was below market, and she pulled out of the deal.
From this point, it becomes murky at which points Herzog was acting as Russell's lawyer, and when he was playing the role of a friend and confident.
The Kirkwoods took proceedings against Russell in mid-2015.
During that legal action, Herzog and Russell began the discussing the possibility of Herzog purchasing the property for $8m - subject to the cancellation of the Kirkwood deal.
Herzog drew up a sale and purchase agreement, he says on Russell's request.
She signed that agreement, "seemingly without independent legal advice" according to the judgment in June 2016.
October 2015 saw a settlement conference for the Kirkwood proceedings.
Russell had engaged Turner Hopkins as solicitors and Neil Campbell QC as barrister for independent legal representation, but neither was present at the conference.
Herzog was present, and agreed to settlement that saw the Kirkwoods paid $3.5m.
Judge Sargisson describes the terms of the settlement as ""surprising given Campbell provided an opinion, sent to Mr Herzog by letter dated 28 May 2015, concluding Mrs Russell had a good case that her cancellation was valid and would be upheld by the Court."
Russell was worried she would have to sell property to cover the $3.5m.
Herzog advised her there were a number of parties interested in her Pukekoe properties, including the director of Pamela Management.
On October 30, 2015, Herzog drew up an agreement saying he would receive a "fair amount" of any sale price above $8m, leaving a blank for the amount.
Russell hand wrote "½" into the blank, according to the judgment.
The $10m sale to Pamela Management was concluded on December 15.
In 2016, the personal relationship between Russell and Herzog deteriorated. In an August 16 email to Herzog, Russell demanded the repayment of the earlier $410,000 loan, which Herzog did promptly repay.
"The tone of the email was harsh and reflected hurt on Mrs Russell's part. She indicated anger at Mr Herzog for no longer paying attention to her," the judgment says.
Then October 21, 2016, Russell's new lawyers, Blackwood Hopkins Law sent Herzog a letter seeking repayment of the $1m. The letter said Russell could not recall why she had transferred the money.
"Regrettably at the time that the sale took place, Russell was extremely stressed and fails to recall the reason that she signed the authority authorising an amount of $1,000,000.00 to be placed into your account," the letter said.
"It is only now in the cold light of day, after a period has passed since these events that Mrs Russell has been able to reflect on these events and realise that a substantial amount of money was advanced to you at that point with no security taken or discussions had over the payment of interest."
Judge Sargisson says the "allegation that there was a loan is disputable ... There is no contemporary documentation to indicate that parties viewed the payment as a loan."
But she did rule the matter should go to a full hearing, where it will be established if Herzog's actions were unconscionable, and that he breached his fiduciary duty by taking advantage of a client who was possibly (in Judge Sargisson's words unable to adequately manage her own affairs.
During the summary judgment hearing, medical certificates were produced from a doctor diagnosing her poor emotional and psychological health.
A case file note was also produced where Herzog instructed Campbell that "CR is vulnerable to being taken advantage of".
A date has yet to be set for the case.
Herzog declined to comment when approached by the Herald.
