In a contentious moment during today’s vice presidential debate, CBS News briefly muted the microphones of candidates JD Vance and Tim Walz. The incident occurred when Republican candidate Vance objected to moderator Margaret Brennan’s attempt to clarify his comments on immigration.

Vance had claimed that illegal immigrants were overwhelming cities like Springfield, Ohio, prompting Brennan to interject that the Haitian residents in that city were there legally. “Since you’re fact-checking me, it’s important to say what is actually going on,” Vance replied. However, as their exchange escalated and the candidates spoke over each other, CBS News opted to cut off their microphones.

Before the debate, CBS had stated that candidates were expected to fact-check one another, leaving moderators Brennan and Norah O’Donnell to facilitate the discussion. Vance contended that CBS was violating this guideline.

The issue of fact-checking has been a recurring theme in political debates this season. Last month, during the presidential debate between Donald Trump and Kamala Harris, moderators corrected Trump multiple times, which led to frustration among Trump and his supporters. In contrast, CNN did not attempt corrections during the Trump-Biden debate in the spring.

During today’s debate, Trump criticized the moderators on his Truth Social platform, labeling them as “extremely biased.”

In another heated moment, O’Donnell emphasized the scientific consensus on climate change while questioning Vance about his running mate’s claim that climate change is a hoax. The moderators also encouraged candidates to address each other’s claims, such as when Brennan asked Walz to respond to Vance’s accusation that the vice president was allowing migrants into the country.

However, the most significant debate over accuracy arose during a discussion on abortion. Vance cited a provision in Minnesota law regarding the care of babies who survive abortion attempts, calling it “fundamentally barbaric.” Walz countered that Vance’s interpretation was incorrect.

Throughout the debate, CBS displayed messages urging viewers to visit its “CBS News Confirmed” website for fact-checks on claims made during the debate. A QR code was even shown to facilitate access to this information via mobile devices. However, this fact-checking initiative was not broadcast on other networks that were simulcasting the debate.

This debate may have been one of the final opportunities for viewers to see representatives from both presidential campaigns interact on screen. While Harris has proposed a second debate with Trump, the Republican candidate has yet to respond.