For most of former special counsel Robert Mueller’s testimony on Wednesday, he refused to offer any opinion or speculation beyond the bounds of his report — except for one remarkable moment when he offered his most direct critique of President Donald Trump yet.

Rep. Mike Quigley (D-IL) asked Mueller to opine on a series of public statements Trump made during the 2016 presidential campaign praising WikiLeaks after the site dropped troves of private emails hacked from the Democratic National Committee and Hillary Clinton’s campaign by Russian actors.

Quigley read out several of these statements (comments the president has sought to distance himself from more recently). “This WikiLeaks is like a treasure trove” was one particularly cringeworthy quote, which Trump made in October 2016.

“Would any of these quotes disturb you, Mr. Director?” Quigley asked Mueller. “How do you react to them?”

“Problematic is an understatement in terms of what it displays, giving some hope or some boost to what is and should be illegal activity,” Mueller responded.

"I love Wikileaks."

"This Wikileaks is like a treasure trove."

"Boy, I love reading those Wikileaks."@RepMikeQuigley asks Mueller to react to Trump's statement's on Wikileaks.



"Problematic is an understatement," Mueller says https://t.co/Nwn1OnEyZi pic.twitter.com/SgLJm2T05s — Bloomberg Politics (@bpolitics) July 24, 2019

Mueller’s statement marked one of the most pointed comments he’s made about Trump’s behavior up until this point. It’s particularly significant given how reserved he’s been about openly criticizing the president and highlights just how concerning he found Trump’s celebration of WikiLeaks ahead of the 2016 election.

In his report, Mueller concluded that he could not bring charges of a criminal conspiracy between Trump or his associates and the Russian government to interfere with the election, though his team documented numerous ties and interactions between members of the campaign and various Russian officials.

And though Mueller’s report details instances of contact between the Trump campaign and Russians that many find disturbing, in his remarks Wednesday he largely declined to comment on those specific incidents, like the Trump Tower meeting between Donald Trump Jr. and a Russian lawyer.

This is why his testimony about the president’s WikiLeaks comments were so revealing. Though his statement was brief, it hinted at just how troubling he’s ultimately found the president’s actions in those instances.