The “Fox & Friends” panel was all set Thursday to scorch the Democrats for closed-door questioning in the impeachment investigation — until Fox’s own legal analyst noted that the setup was approved by Republicans.

Former judge Andrew Napolitano explained that House Republicans were protesting their own rules for impeachment investigations when they stormed the closed-door session on Wednesday. The questioning took place in a secure room to protect possible classified information.

The “initial level of inquiry” in an impeachment probe can be conducted “in secret,” as sanctioned in rules passed by the GOP, Napolitano noted.

“I read the House rules, and as frustrating as it may be to have these hearings going on behind closed doors, the hearings for which Congressman [Adam] Schiff is presiding, they are consistent with the rules,” Napolitano said.

It was January 2015 and Republican John Boehner was the speaker of the House when the rules were written, he noted. “Who enacted them? A Republican majority.”

Napolitano compared the current questioning to what goes on during a grand jury investigation, which is never public, even though a subsequent trial is.

What’s going on now “are not the impeachment hearings,” Napolitano explained. “Eventually, there will be a public presentation of this, at which lawyers for the president can cross-examine ... and challenge” witnesses, he added.

As for the Republican lawmakers’ “protest,” Napolitano said: “I get it. The Republicans are frustrated and they wanted to make a point ... but this is just not the most effective way to show respect for what your colleagues are doing.”

Witness interviews during President Richard Nixon’s and President Bill Clinton’s impeachment investigations were also conducted behind closed doors initially, Napolitano noted.

Republicans held a closed-door investigation into former Secretary of State Hillary Clinton over the 2012 terror attacks in Benghazi, Libya. Their final report on the probe argued that closed hearings were more productive when seeking the truth.

Check out what else Napolitano had to say in the video above.