The messages from Honey included a tip-off about Eroad's United States sales data in 2015.
The confidential data showed the publicly listed Kiwi company - which also operates in Australia and the US - was performing badly as it attempted to break into the North American market.
Just days after Sansom received the texts he sold 15,000 of his shares in the company.
Honey's September 22, 2015 message to Sansom read: "US sales not doing [too well], time to sell up? Confidential obviously."
It also included a photo of an executive sales summary.
"You're a bad boy, but thanks!" Sansom replied.
On September 24, 2015, when Sansom sold the shares he did so at a price of $3.41 each.
Four days passed before news of Eroad's US sales setback went public, crashing its stock price.
The announcement resulted in the biggest daily and weekly fall in Eroad's trading history, since its initial public offering in August 2014.
By October 2, 2015, its shares were trading at $2.60 each - dropping by 21 per cent.
A few days later Honey messaged Sansom stating, "I hope you sold."
Sansom replied: "Yep, I sold as much as I could but still have lots left. Not many buyers out there."
The court heard during the trial that Sansom had been on Eroad's executive management team after a lengthy career at Vodafone - where he now works again - and was responsible for a team that included Honey as insights and analytics manager.
Sansom hired Honey after the pair grew friendly while working at Vodafone.
Sansom's counsel, David Jones, QC, argued at trial that his client was simply smarter than everyone else and had analysed market trends.
"This man looked at the numbers and he worked it out for himself. He had planned to sell the Eroad shares for months.
"It's not rocket science, it's just being smart and being perceptive," Jones said.
"You can't be penalised for being smarter than someone else for analysing material and this man is an analyst."
Honey, the first to be criminally prosecuted for insider trading in New Zealand, was sentenced last year to six months' home detention for sending the messages.