That business case, presented behind closed doors in July 2015, has never been released to the public despite repeated requests for it.
Wilson said the initial presentation lacked details around:
• User numbers
• Costs, except that it could potentially be in the tens of millions
• Alternatives - none were offered.
"I was never convinced going with the American organisation was the right one," he said.
"Their [Simcock and Murray] explanation was they wanted to be the first taxi off the rank and if it was a success then Waikato DHB could derive the benefit if it was circulated among other DHBs.
"We would be the lead licence and were going to glean a potential revenue at the result of other DHBs signing up. I felt it probably wasn't our core business."
Wilson said Murray, primary and integrated care clinical director Dr Damian Tomic and virtual care and innovation executive director Darrin Hackett, visited him at work on July 8 to convince him of HealthTap's merits because he had been unable to attend a workshop.
"We were still a DHB grappling with high costs of doing the campus redevelopment and there was a lot of pressure on minimising expenditure. They didn't [convince me]."
Wilson, who left the board in September last year, levelled criticism at Simcock saying: "I felt Bob was driving a lot of this and I didn't think it was his job.
"He was captivated by it. Here was a project that came out of the blue, was driven by the chairman, and in the first meeting it was: 'This is an amazing opportunity, we've got to act now, I need your authority, we're going to do this'."
Wilson said he suggested looking at other options first including a tele-health system being developed at the time by Pinnacle Midlands Health, which represents 400 GPs across the region.
It's understood the DHB was already working with Pinnacle towards sharing the My Indici system before Murray was appointed CEO.
Another former board member, Andrew Buckley, said he would have preferred to support local providers, but Simcock only promoted HealthTap.
"All I can remember is Bob telling us it was the way to go. 'We've looked into this model and it was working well in America, so why would we not go with it?' It was a matter of trust really.
"You'd expect the background investigations and due diligence to be presented to the board rather than the board do it themselves."
However Simcock said the board would not have endorsed the staff recommendation if it was not satisfied it had sufficient information to go ahead with the two-year trial of HealthTap.
"I believe the board carried out its due diligence in this matter properly and the decision, which followed many months of evaluation by staff, was not rushed."
He said the board decided to go with HealthTap because it believed it was the only service that would meet its needs.
"This was a considered decision made by the full board."
Meanwhile Simcock dismissed allegations Murray's lawyers tried to shut down any investigation into SmartHealth with his resignation earlier this month.
Simcock said the DHB decided to use the HealthTap platform on the basis there would be a review of its use after two years.
"Nigel Murray was always aware of that. I can see no relationship between his decision to resign and that review."
