Donald Trump raised plenty of questions during tonight’s presidential debate by seeming to admit that he hasn’t paid any taxes in some years—and then later denying it in interviews with the media. The Republican nominee has refused to release his tax returns, and that refusal has become a major campaign issue, with 60% of Fox News voters saying they believe Trump is hiding something in his returns.

During a discussion of Trump’s refusal to release his tax returns, Clinton chimed in with a strong claim, stating that his reason for not taking that step is because, “Maybe he doesn’t want the American people, all of you watching tonight, to know that he’s paid nothing in federal taxes because the only years that anybody has ever seen were a couple of years when had he to turn them over to state authorities when he was trying to get a casino license, and they showed he didn’t pay any federal income tax.”

In response, Trump didn’t contradict her assertion, but quipped: “That makes me smart.”

Later, Clinton repeated the claim: “He paid zero. That means zero for troops, zero for vets, zero for schools or health. And I think probably he’s not all that enthusiastic about having the rest of our country see what the real reasons are, because it must be something really important, even terrible, that he’s trying to hide. And maybe it’s because you haven’t paid any federal income tax for a lot of years.”

To which Trump again didn’t contradict her but replied, “It would be squandered, too, believe me.”

But later, in post-debate interviews with CNN’s Dana Bash and Jim Acosta, Trump insisted that he has paid federal taxes. When Bash asked him about it, he denied implying he hadn’t paying taxes, adding “If they said I didn’t, it doesn’t matter.” Later, he told Acosta, “I’ve paid federal taxes,” without explaining whether there have been years that he’s avoided paying taxes.

Later, the Clinton campaign tweeted a video of that exchange, stating: “Paying zero in taxes doesn’t make you ‘smart.’ It makes you a tax evader.”