Nope, silly one....
No one called in to testify for for 3, 8, 10 hours is allowed to be public testimony. You interview to find out things you didn't know, then fo!low leads and interviews from there and find out more in the new lead interviews etc.
This is never done in public, because investigators do not want to tip off the future related witnesses, to what the previous witness said.
They could call him to testify publically, after the private under oath testimony and followup.
Bannon doesn't get to set the terms. What an arrogant felon, or arrogant pardoned felon!
The judged drilled him a new exit hole, on his requests!