The Second Circuit has held that a restriction on a criminal defendant's right to discuss his testimony with his attorney can violate the Sixth Amendment. In this case, the defendant was being cross examined and the court recessed until the following morning. The court prohibited defense counsel from discussing the testimony with his client.
In United States v. Andrews, 05-2630-cr, Judge Guido Calabresi wrote for the circuit that a "defendant's constitutional right to consult with his attorney on a variety of trial-related issues during a long break, such as an overnight recess, is inextricably intertwined with the ability to discuss his ongoing testimony. Thus, a ban on discussing testimony during a substantial recess does materially impede communication of a 'constitutional quality.'"