“Am I going to have to like Bolton now?” Bradley Moss, a national security lawyer frequently critical of the Trump administration, tweeted earlier this month. “This plot twist, where John Bolton turns out to be good, really strains the credibility of this entire season,” joked Vox.com writer Ian Millhiser.

In remarks he’s made since leaving the administration in September, Bolton has blasted Trump’s outreach to North Korea as “doomed to failure” and ripped his negotiations with the Taliban as “disrespectful” to the families of 9/11 victims.

He hasn’t publicly described what others have depicted as a fierce internal battle among aides and associates of Trump over the thrust of U.S. policy toward Ukraine, however. Privately, some observers suspect whatever Bolton ultimately says could damage the president.

Am I going to have to like Bolton now? https://t.co/6wGEZxiye4 — Bradley P. Moss (@BradMossEsq) October 15, 2019

On Tuesday, William Taylor, the top U.S. diplomat in Ukraine, offered the most detailed account yet portraying Bolton — a famously hawkish conservative known for his bureaucratic knife-fighting skills and loathing of liberals — as growing irate at the possibility that Ukraine policy was being warped by Trump’s political ambitions.

In testimony before House lawmakers, Taylor said he was told by Fiona Hill and Alex Vindman, both National Security Council officials at the time, that Bolton “abruptly ended” a July 10 meeting with Ukrainian officials. He did so after Gordon Sondland, the U.S. ambassador to the European Union, “connected” a potential Trump meeting with Ukraine’s new president, Volodymyr Zelensky, with “investigations.”

As he ended the meeting, according to Taylor, Bolton told Hill and Vindman that “they should have nothing to do with domestic politics.” Bolton told Hill, who has also since left the NSC, that she should “brief the lawyers.” Bolton also opposed setting up a call between Zelensky and Trump “out of concern that it ‘would be a disaster,’” Taylor testified.

Taylor’s statements aligned what Hill told lawmakers earlier. He confirmed a particularly colorful line from Hill: that “Bolton referred to this as a ‘drug deal’ after the July 10 meeting.”

Hill also told lawmakers that Bolton described Rudy Giuliani, Trump’s personal attorney, who also was helping shape Ukraine policy, as “a hand grenade who’s going to blow everybody up.”

Bolton was not on the July 25 phone call between Trump and Zelensky that is at the core of the impeachment probe. According to a detailed readout of that call, which Trump has defended as “perfect,” Trump repeatedly pressured the new Ukrainian leader to investigate Joe Biden.

Trump pushed Bolton out of the national security adviser role in September, after months of rising tensions between the two, describing him as “tough” but “not smart.” He also complained, “John wasn’t in line with what we were doing” — remarks that at the time were interpreted to refer to Bolton’s widely reported disagreements with the president over Afghanistan, Iran and North Korea.

Bolton’s firing came at almost exactly the same time that the Trump administration agreed to unfreeze some $400 million in military aid to Ukraine — money that Taylor came to believe was being held up to pressure Kiev into pursuing Trump’s desired investigations.