“How much have you taken from Peabody Coal?”

That was the question Greenpeace researcher Jesse Coleman asked prominent climate change skeptic and Princeton physicist William Happer in a Senate hearing room Tuesday afternoon, just as Happer was preparing to testify before Sen. Ted Cruz’s Commerce subcommittee.

Hours earlier, Happer had been exposed as one of the two victims of a sting in which Greenpeace researchers posed as consultants for the fossil fuel industry. They got Happer and a Pennsylvania State University professor to agree to accept funding to produce pro-industry research while concealing the source of that funding.

Happer was none too pleased with Coleman’s question.

“You son of a bitch, I haven’t taken a dime!” replied Happer. “I haven’t taken a dime, you son of a bitch.”

Watch the exchange:

In fact, in email exchanges he thought he was having with a business advisory firm based in Beirut, Happer had described his convoluted remuneration agreement with Peabody Coal: His fee, in return for his testimony at a regulatory hearing in Minnesota, was to go not directly to him, but to a nonprofit that paid some of his expenses.

The other sting victim was Frank Clemente, a professor emeritus of sociology at Penn State known for his pro-coal views. He received an email in which  Greenpeace U.K. investigators Lawrence Carter and Maeve McClenaghan posed as a fixer for an Indonesian energy company. They asked him to produce a “briefing paper” to “counter damaging studies on Indonesian coal deaths, which have appeared in run up to Paris [climate talks].”

Clemente replied that he would be “very interested” in the project, noting that he had “worked with the Coal Industry Advisory Board, International Energy Agency, World Coal Association, the American Coal Council and the NCC, as well as a number of private coal-based companies and groups.”

Clemente explained that he could be cited using his academic title, that there was “no requirement to declare source funding in the U.S.,” and that all of his writing has “been published under the rubric of me as an independent scholar.”

Citing an hourly rate of $275, he sent over a paper he did for the International Energy Agency that he said cost them $50,000. An “8-10 page paper” would run $15,000. “My op/ed fee usually is $6,000 for 2-3 pages.”

He attached his testimony before the Tennessee Valley Authority and an op-ed about coal that was picked up by dozens of small publications. “Note that in none of these cases is the sponsor identified,” he boasted. “All my work is published as an independent scholar.”

In their dealings with Happer, the Greenpeace researchers posed as a “partner in a business advisory firm based in Beirut” advising an exploration and production firm.

They wrote that their client was “concerned about the impacts of the U.N. climate talks later this month” and wanted to “commission a briefing … which highlights the crucial role that oil and gas have to play in developing economies.”

Happer responded by attaching a white paper he helped write for the CO2 Coalition, a pro-carbon organization, as well as testimony at a regulatory hearing in Minnesota. “I would be glad to try to help if my views, outlined in the attachments, are in line with those of your client,” he said.

Happer explained that “whatever fee” they paid should “go directly to the CO2 Coalition. This was the arrangement I had with the attorneys representing the Peabody Coal Company in the regulatory hearings in Minnesota. The fee I would have received was sent instead to the CO2 Coalition, a 501(c)(3) tax exempt educational organization. The CO2 Coalition covers occasional travel expenses for me, but pays me no other fees or salary.”

Penn State and Princeton did not respond to requests for comment. Like many universities, Penn State explains on its website that it only requires public disclosure of conflicts of interest on research that receives certain kinds of federal research money.