"The family had opposed the unescorted leave on the grounds that it imposed an extreme risk to Nicholas' safety, and have since discovered that on the day he went missing, Nicholas had been let out unescorted on at least six occasions before he finally disappeared - in contravention of the hospital's own 'management plan' for Nicholas."
Mr Macpherson acknowledged the funding application was unusual but in a letter he gave to board members, said it was vital that his son and family's interests receive the same level and quality of legal representation as the DHB, in order to achieve a fair process.
"DHB legal representation is fully funded by the New Zealand taxpayer, including a portion of our own taxes.
"It would be grossly unfair to the family, which comes nowhere near qualifying for standard legal aid, for us to either be denied quality legal support, or for the family to have to pay for that themselves."
Mr Macpherson told the Herald the odds were against the family because to pay their legal expenses would set a precedent.
"From our point of view we hope there is such a precedent. It's pretty appalling when you think about it that people in that situation pay to find the truth out in what's happened to their loved ones, while the people who were responsible get funded by the taxpayer to try and explain it away."
The Herald understands it's the first such request of the DHB and it has put off a decision until legal advice can be sought.