This is why you should not impeach a president in secret. Look at these tactics. With a less strong-spited witness, this kinds of questioning, which one expects on a police state, would not occur.
According to Byron York in the Washington Examiner:
In a secret interview, Rep. Adam Schiff, leader of the House Democratic effort to impeach President Trump, pressed former U.S. special representative to Ukraine Kurt Volker to testify that Ukrainian officials felt pressured to investigate former Vice President Joe Biden’s son Hunter as a result of Trump withholding U.S. military aid to Ukraine.
Volker denied that was the case, noting that Ukrainian leaders did not even know the aid was being withheld, and that they believed their relationship with the United States was moving along satisfactorily, without them having done anything Trump mentioned in his notorious July 25 phone conversation with Ukrainian President Volodymyr Zelensky.
When Volker repeatedly declined to agree to Schiff’s characterization of events, Schiff said, “Ambassador, you’re making this much more complicated than it has to be.”
The interview took place October 3 in a secure room in the U.S. Capitol. While the session covered several topics, the issue of an alleged quid pro quo — U.S. military aid in exchange for a Ukrainian investigation of the Bidens and a public announcement that such an investigation was underway — was a significant part of the discussion.
“[The Ukrainians] didn’t want to be drawn into investigating a Democratic candidate for president, which would mean only peril for Ukraine, is that fair to say?” Schiff asked Volker.
“That may be true,” Volker responded. “That may be true. They didn’t express that to me, and, of course, I didn’t know that was the context at the time.” (Volker has said he did not know that Trump had mentioned the Bidens on the July 25 call with Zelensky until the rough transcript of the call was released on September 25.)
“Part of the other context is vital military support is being withheld from the Ukraine during this period, right?” Schiff asked.
“That was not part of the context at the time,” Volker said. “At least to my knowledge, they [Ukrainian leaders] were not aware of that.”