A "short, sharp" culture review of the organisation is also being carried out by lawyer Debbie Francis, but board chairperson Paula Bennett says it has not reached the point where senior leaders would lose their jobs.
Both appeared at the Health Select Committee on Monday afternoon to answer questions about the drug-buying agency along with chief executive Sarah Fitt.
Seymour told the MPs he had received assurances Pharmac would reinvestigate the decision to exclusively fund the Mylan-branded hormone replacement therapy (HRT) patches as a treatment for menopausal women - no longer providing the Estradot brand - from July 2025.
"They can't guarantee what the outcome will be, but I would hope that you'll actually see a different decision come out the other side," he told reporters afterwards.
"No one is denying that the HRT project has been done badly ... the consultation wasn't proper."
He noted the decision was yet to take effect, and said he expected the problem to be fixed in that time.
"How they will do that will be up to them, but I feel that there's time to fix it and get the result."
The funding decision followed a global shortage of the patches and meant a reliable supply, but the loss of funding for Estradot prompted an outcry and petition from women who had found it more effective than other brands, and produced fewer side effects.
Seymour had last week sought an explanation from the agency about an apparent lack of consultation with the patients affected.
He said it was not his place to interfere with the senior leadership, but he had confidence in Bennett and was pleased with the board's performance.
"So look, I know it's a mixed message in a way, but Pharmac is doing much, much better than ever before, but they dropped the ball on this one thing that they're now fixing."
Pharmac had initially pushed back against some of the criticism over the decision, and said consultation had taken place through the tender process, but Bennett said that was not good enough, and the agency had dropped the ball.
"I don't call that consultation at all. And I made that very, very clear to the chief executive," she said.
She believed the agency had been too focused on ensuring a reliable supply during the global shortage, but there were still other questions that needed answering.
"Why you sort of couldn't do both? They would give you an answer as to why they couldn't, you know, they just believed that.
"There were times where Estradot was doing less than 50 percent ... of what was needed, so you're kind of trying to guess how much they will be able to supply ... but we should have consulted. I mean, if we'd consulted we would have heard these voices and we wouldn't have caused this level of anxiety.
"I apologise on behalf of Pharmac, I was blindsided as well. I think we need to take responsibility, and I think we need to acknowledge that they did not consult."
Someone in the senior leadership team had marked the decision as "not contentious," which meant it would not be flagged up to the board, but it was not at the point where anyone would lose their jobs just yet, she said.
"No, I think we need to keep it in perspective so they've missed a vital step. There is time to fix it. They are listening, and they've owned the mistake. No one, no organisation, is ever going to be 100 percent right all of the time."
"Being transparent, open and consulting is non-negotiable, and they've dropped the ball on this one. I expect better, I will be demanding better and at the next board meeting, they will be bringing what went wrong, how they're going to change it, and ... we'll be talking about the red flags."
The select committee hearings were part of the second-ever "scrutiny week", where select committees grill ministers and agency heads about their performance and the government's plans.
The way committee chairs handled the inaugural scrutiny week earlier in the year left some opposition MPs frustrated, and that was again the case in the short initial session with Seymour after the chair, Sam Uffindell, set out his rules around the number of questions.
Uffindell had to call for order at one point, and Seymour later said he agreed "that scrutiny's been a bit shallow" by the opposition MPs.
Labour's Glen Bennett fired back: "We don't have a chance to actually delve into it, I guess, is a bit of the problem".
Seymour later said he welcomed more questions, and in his view a select committee hearing should have two-thirds of the time dedicated to opposition MPs.
"I don't want to criticise the chair. I mean, he's doing his best there. But certainly all my experience of select committees is, you know, let it flow and have a bias towards the opposition."
