What is the scope of a federal district court's authority to order discovery under Rule 16 of the Criminal Procedure 16?

We review de novo the district court's rulings on the scope of its authority to order discovery under Federal Rule of Criminal Procedure 16. United States v. Mikaelian, 168 F.3d 380, 389 (9th Cir. 1999). "[A] violation of Rule 16 does not itself require reversal, or even exclusion of the affected testimony." United States v. Figueroa-Lopez, 125 F.3d 1241, 1247 (9th Cir.1997). "`The prejudice that must be shown to justify reversal for a discovery violation is a likelihood that the verdict would have been different had the government complied with the discovery rules, not had the evidence been suppressed.'" United States v. Baker, 10 F.3d 1374, 1398 n. 8 (9th Cir.1993).