Can a witness not at the time under examination be excluded from the courtroom?

The trial court "may exclude from the courtroom any witness not at the time under examination so that such witness cannot hear the testimony of other witnesses." (Evid. Code, 777, subd. (a).) "The courts of this state have consistently held that the violation of a witness exclusion order [citations] does not render the witness incompetent to testify, and does not furnish grounds to refuse permission to testify, at least where the party who seeks to offer the testimony was not 'at fault' in causing the witness's violation of the exclusion order. [Citations.]" (People v. Redondo (1988) 203 Cal.App.3d 647, 654; People v. Adams (1993) 19 Cal.App.4th 412, 436.)