Hillary Clinton let her frustration with the contentious primary spill into the open in New York on Thursday night when confronted by a Greenpeace activist over accepting donations from employees of the fossil fuel industry.

While walking the rope line, Clinton was confronted by Eva Resnick-Day, who asked the Democratic frontrunner: "Will you act on your word to reject fossil fuel money in the future in your campaign?"

A video of Clinton's passionate response ricocheted around the internet. "I do not have, I have money from people who work for fossil fuel companies," Clinton said, her voice rising. "I am so sick of the Sanders campaign lying about me! I’m sick of it."

This is about donations from private individuals tied to fossil fuel companies

In the video, the Greenpeace activist asks Clinton to "reject fossil fuel money."

The problem with this question is that Clinton doesn't take any money from the fossil fuel industry; election law forbids candidates from taking money directly from corporations, and nobody is claiming that Clinton did so. (This may be why Clinton began her response with, "I do not have...")

Clinton's spokesperson pointed this out in a statement after the video of the exchange surfaced. "The simple truth is that this campaign has not taken a dollar from oil and gas industry PACs or corporations," the statement said.

The activist's question makes more sense if interpreted to be about Clinton's decision to take money from private individuals who have ties to the fossil fuel industry. Bernie Sanders's campaign issued a statement to this effect, criticizing Clinton for taking money from lobbyists connected to the oil, gas, and coal industry.

"In fact, 57 oil, gas and coal industry lobbyists have directly contributed to Clinton’s campaign, with 43 of them contributing the maximum allowed for the primary," a Sanders spokesperson said in a statement.

What the Greenpeace attack against Clinton is overlooking

But this doesn't really amount to a meaningful critique of Clinton, either.

Greenpeace has leveled two main attacks again Clinton: 1) that the Super PAC supporting her campaign, Priorities Action USA, has received more than $3 million in donations from those connected with the fossil fuel industry, and 2) that Clinton's campaign has taken $309,107 from "people working for fossil fuel companies."

The first criticism is particularly weak, because Clinton is legally prohibited from coordinating with the Super PAC. So there's not much she could do about the vast majority of the donations fueling Greenpeace's attack — even if she wanted to.

The second is a little trickier for Clinton to deflect, in part because she could theoretically have her campaign return all donations raised by those tied to oil or gas companies.

But this one doesn't really add up, either. For one, Sanders himself has accepted more than $50,000 from the same category of donors, according to MSNBC. There's no indication he plans to return that money.

"You could certainly try to set up a system where you routinely refund contributions from those tied to oil and gas," says Bob Biersack, a senior fellow at the Center for Responsive Politics. "You could do it, theoretically, but I can't think of an example of it ever being done."

How the critique of Clinton gets at a broader truth about campaign finance

Clinton's acceptance of gifts from individuals in these industries is standard practice for the vast majority of presidential candidates, Biersack said. Barack Obama, for instance, got more than $400,000 from oil and gas industry employees during his 2008 run, according to the Washington Post.

But from another perspective, this is exactly the point of Sanders's critique: that the standard practices in Washington, DC, are deeply corrupt.

"The definition of routine and acceptable might be changing," Biersack said. "It's an example of how the normal process works, but the normal process could be considered pretty flawed."

Months ago, Greenpeace asked Martin O'Malley, Sanders, and Clinton to refuse to accept "fossil fuel" money. Both O'Malley and Sanders signed the pledge, but Clinton didn't.

In one narrow sense, all that means is that Clinton wasn't willing to promise more than she could deliver. If signing the pledge meant refusing donations from everyone who worked in the industry, Sanders has violated it.

Still, it's easy to understand why activists view the pledge as more than just symbolic.

Clinton's refusal to sign the pledge sends a signal that she is less hostile to these industries than her rivals. It's no coincidence that donors connected to oil and gas have continued to pour into Clinton's coffers and her Super PAC, while Sanders has relied primarily on a essentially unprecedented army of small donors.

"This is an example of what happens when somebody is a mainstream candidate," Biersack said of Clinton's donations. "This doesn't show any indication that she goes looking for oil and gas money. ... Given the piddly amounts we're talking about relative to her whole campaign, this is an example of the way the world works."

That's true. But if you think the way the world works is deeply broken, Clinton's willingness to accept standard practices looks deeply problematic too.