CNN  — 

Last week in Iowa, a man at a Joe Biden town hall asked the wrong question.

The man wanted to know why Biden would be better than President Donald Trump since the former vice president had sent his “son over (to Ukraine), to get a job and work for a gas company, that he had no experience with gas, nothing.” To which Biden reacted very angrily. “You’re a damn liar, man, that’s not true,” Biden said. “And no one has ever said that, no one has proved that.”

Which is true! There is zero evidence that Biden had any active role in the appointment of his son, Hunter, to the board of Burisma Holdings, a Ukrainian natural gas company, in 2013.

But what was lost amid the exchange – and Biden’s angry response – was there is still a very real question that Biden should continue to be asked and needs to find a clearer answer for. And it’s this:

“Do you think it was appropriate for your son to be on the board of a Ukrainian company – and being paid $50,000 a month in that role – while you were the vice president of the United States?”

That question is a) fair b) totally worth asking and c) something Biden should be required to answer, beyond what he has said publicly so far.

Why? Because there is very little to suggest that Hunter Biden had anything in his background that would make him an expert on Ukraine, natural gas or Ukraine natural gas. In fact, the only seeming credential he had to be on a board of any sort of company like Burisma was his last name – and that he shared it with the sitting vice president of the United States.

Hunter Biden himself had admitted it was “poor judgment” to be on the board. He did so in an October interview with ABC, adding: “Did I do anything improper? No, not in any way. Not in any way whatsoever.”

Which is totally fine! Simply being on the board is no evidence of wrongdoing of any sort. But it is odd – especially a) Hunter’s seeming lack of credentials for a role like that and b) the large sum he was reportedly paid for that role.

To date, Joe Biden has been reluctant to engage on questions about Hunter. He’s been able to do so – in large part – because President Donald Trump has said a slew of untrue things about both Bidens. Biden has been able to simply note – rightly – that all of Trump’s allegations about how Biden forced the removal of Ukraine’s top prosecutor in 2016 in order to keep that prosecutor from looking into his son are false.

But move the conversation away from Trump’s false accusations and ground the conversation in established facts about Hunter’s role at Burisma and his compensation in that gig, and it becomes clear that Biden’s answers still fall short.

Asked by Axios’ Mike Allen in an interview that aired Sunday night regarding his defense of his son, Biden said this: “I don’t know what he was doing. I know he was on the board. I found out he was on the board after he was on the board and that was it.” Pressed by Allen on whether Biden – as a candidate for president – was interested in getting to the bottom of how his son got on the Burisma board, the former vice president responded: “No. Because I trust my son.”

Really? I mean, I get trusting your son. But Biden’s son has already said publicly that being on the board was “poor judgment!” And it’s an absolutely worthy question for someone who wants to be president of the United States: Do you think it was a mistake for your son to be on the board of a Ukrainian natural gas company being paid a large sum for it while you are the vice president of the United States?

Biden can get angry. He can get up in arms. But he really should get used to answering the question.