He was using the school's email and devices for his personal use because of the long hours he was working, he said, and directed his personal correspondence there.
The pornographic images found on his device were all "sent to me by email over the years", he said, and were not solicited by him and neither did he go looking for them online.
"They came from principals, ministry [of Education] personnel, police, who are good friends of mine," he said.
The devices - a desktop computer, laptop, smartphone and iPad - were password protected and only ever in his possession, he said, and were not able to be accessed by pupils. However, he admitted he had not taken specific steps to prevent them being accessed by the children.
At the time he considered the images "raunchy" and "jokes" between mates, rather than pornographic, he said. But had come to the realisation that they were disrespectful and inappropriate.
He agreed on questioning that the material was of a moderate to high grade pornographic nature.
"This has been the most embarrassing thing for me. While I didn't go on the internet looking for those images, I allowed them to be emailed to me from my mates," he said.
"When they started some years ago, I didn't think anything of it. As my young girls grow into young women I started seeing things a little differently.
He now acknowledged the images were inappropriate and disrespectful to women "because it minimises and devalues a woman's mana".
Five other staff members were also found to have sent pornography to or from school emails.
The school had a security filter in place for school computers to prevent pornographic or objectionable images being accessed around children, he said, but admitted he had disabled this feature on his own devices.
He claimed this was so he could access sites such as TradeMe, but allowed that it also meant he could receive the inappropriate emails from friends.
When asked why the inappropriate emails were never deleted from his email account - amounting to 1522 photographs and/or videos attached or embedded to 245 emails - he said he was a "hoarder" and "struggled to throw things out".
There was also an element of feeling "bullet-proof", he admitted, because some of the emails were sent to him from a police officer friend.
"Some were from a policeman so I thought, 'they're fine, they're from the cops'."
The man was also charged with mismanagement of the school finances, and today admitted some culpability, saying he was naive and relied too heavily on the financial ability and advice of others.
New principals were not given financial or management training, he said, so he relied on previous practices, school staff and the board of trustees.
The tribunal heard how during his time at the school $100,000 went missing from a school savings account. After thorough investigation by an auditor, the Ministry of Education and an accountant, no explanation for its disappearance was found, and no individual was found to have stolen it.
There is no implication that he stole the money.
In a separate incident, an office administrator was charged with stealing $30,000 from the school during this time.
Financial mismanagement highlighted to the tribunal included the use of pre-signed cheques, which were used by teachers in his absence or on school trips to buy items for the children.
Staff members were granted advances on money, and the principal admitted racking up $10,000 over the course of a year - mostly in fuel expenses for his own travel - which he allowed to build rather than pay off regularly.
He admitted he took advantage of the fact he was principal to pay his expenses back at his leisure. His wife and mother were also allowed to use school fuel cards.
The principal kept his expenses noted in a system that was referred to as "the yellow book". He told the tribunal he believed this system meant he was being open and transparent in his transactions, and would safeguard him from accusations of dishonesty.
He believed that as long as the money was paid back by the end of the school year, it was ok, and it wasn't until the charges were brought against him that he realised it amounted to "using the school as a bank".
"I did not in all truth know I was doing anything wrong," he said, later adding: "I have been given many lectures since by a colleague."
The tribunal members reserved their decision.
