Ben Carson is upset at CNBC, and he’s asking the other candidates to help him demand that future debates must avoid ‘gotcha’ questions.

“Debates are supposed to be established to help the people get to know the candidate,” Carson said at a news conference before a speech at Colorado Christian University. “What it’s turned into is — gotcha! That’s silly. That’s not helpful to anybody.”

What does Carson consider a “gotcha” question? What got him so upset? CNBC moderator Carl Quintanilla’s question about Carson’s long relationship with a quack nutritional supplement company that claimed their products could cure autism and cancer.

“The questions about Mannatech are definitely gotcha questions,” Carson said. “There’s no truth to them. I know people know how to investigate. They can easily go back and find out I don’t have any formal relations with Mannatech. They can easily find out that any videos I did with them were not paid for, were things I truly believed. That would be easy to do. If they had another agenda, they could investigate and say — see, there’s nothing there! But if they have a gotcha agenda, they conveniently ignore all the facts and try to influence public opinion.”

So the question that got under Carson’s skin was really a question about his ethics and his honesty — which would seem to be perfectly appropriate things to ask a candidate for President of the United States.

And Carson’s denials that he had “formal relations” with Mannatech only serve to drive home the point that he’s not being totally honest about this issue.

As the Wall Street Journal reported earlier this month, Carson’s relationship with the company deepened over time, including “four paid speeches at Mannatech gatherings, most recently one in 2013 for which he was paid $42,000, according to the company.” The company disputes that Carson was a “paid endorser or spokesperson,” according to the Journal, and claims his financial compensation went to charity.

National Review also highlighted Carson’s connections to Mannatech in January and how Carson’s team went to great lengths to distance themselves from the company. Some of his video appearances have been removed from the Internet, but those that remain appear to show a deeper affiliation than Carson claimed during Wednesday’s debate.

In one video for Mannatech last year that remains online, Carson discusses his experiences with nutritional supplements while seated next to the company’s logo. “The wonderful thing about a company like Mannatech is that they recognize that when God made us, He gave us the right fuel,” Carson explained. “And that fuel was the right kind of healthy food … Basically what the company is doing is trying to find a way to restore natural diet as a medicine or as a mechanism for maintaining health.”