Former National Security Council aide Fiona Hill clashed with Republicans during Thursday’s Trump impeachment inquiry hearings after accusing some lawmakers of embracing the “fictional narrative” that only Ukraine -- and not Russia -- interfered in the 2016 elections, igniting a fierce response.

The testy proceedings at the Capitol also included testimony from David Holmes, a U.S. State Department official in Ukraine, who described how he overheard a phone call this summer with President Trump about wanting Ukraine to conduct political investigations.

Holmes testified that he eventually understood that “demand” to be linked to delayed military aid. The White House countered, as it has in prior hearings, that the witnesses did not speak to any direct knowledge on the aid hold-up, while GOP lawmakers dismissed the alleged offense as nothing more than a “thought crime.”

But Hill irritated Republicans from the outset Thursday by saying in her opening statement, “Based on questions and statements I have heard, some of you on this committee appear to believe that Russia and its security services did not conduct a campaign against our country—and that perhaps, somehow, for some reason, Ukraine did.”