Joe Biden denies that he fat-shamed Iowa voter during fiery debate, campaign offers an improbable cover story

Former Vice President Joe Biden denied that he was caught on video fat-shaming a man who confronted him at his event, and his presidential campaign instead offered an improbable cover story.

Video of the fiery debate between Biden and an angry critic at his campaign event went viral on Thursday.

Many believed that Biden was beginning to say "fatso" to the argumentative man during the exchange.

Biden's senior adviser Symone Sanders took to her Twitter account to explain why people didn't hear on the video of the altercation what their ears told them they heard.

"Let's be clear RE: the exchange VP Biden had with a voter in Iowa earlier today: 1) the gentleman is a self identified Warren supporter who said he would vote for the VP in a general election 2) his facts were flat-out wrong and 3) the crowd backed VP Biden up in his response," Sanders tweeted.

"To be clear: Any assertion VP Biden said a word about the gentleman's appearance is making this something it is not. In the latter part of the exchange, the VP began to say "Look, facts" then said "here's the deal." If you've been to a Biden event, you've heard this before," she said in a second tweet.

"These lies will not go unchecked & we'll continue to lay out the facts," Sanders concluded helpfully.

Biden himself denied that he used the word "fat" later to Bo Erickson of CBS News.

"No I didn't!" he responded. He did not answer when asked to clarify what it was he said to the man.

Here's the video of the exchange:

Biden Has Tense Exchange With Voter Over Age, Son Hunter: 'You're A Damn Liar' | NBC Newswww.youtube.com