486 F.2d 498, 506-07 (5th Cir.1973) (noting that “although the presence of the Assistant United States Attorney at application proceedings held under Rule 17(b) violates the rule,” “to obtain a reversal of the conviction, defendant is required to show that he was prejudiced by the failure to comply with the rule,” and concluding that defendant “failed to make such a showing”); see also United States v. Hauk, 412 F.3d 1179, 1194-95 (10th Cir.2005) (discussing the third prong of the plain error test, which requires a showing that the alleged error affected substantial rights). For example, Mr. Wardell makes no attempt to link the denial of the subpoenas to the district court’s decision to allow the government to be present. Cf. United States v. Abren, 202 F.3d 386, 391 (1st Cir.2000) (<HOLDING>); cf. also United States v. Gonzalez-Huerta,
recognizing district court application of the same rule holding that the district court was in error in not handling the entire application for defense expert services on an ex parte basis and that on remand the court should hear ex parte only new matters that counsel  refrained from presenting before on grounds of privilege or confidentiality and then reconsider whether it should grant the application holding in case where the asserted defense to plaintiffs contract action to recover fees for his professional services was that the professional services were for the unlicensed practice of law in new jersey and that the contract was therefore illegal and unenforceable that questions of unlawful practice of law will turn on the particular facts presented that the issue could be determined only on a full and complete appreciation of the events and surrounding circumstances that the trial court not evaluate the merits of appellees affirmative defense without reference to matters outside the pleadings and therefore that judgment on the pleadings was not warranted holding that a decision to limit a new rule of criminal constitutional law to prospective application can be based on a balancing of the purpose of the new rule the reliance placed on the previous view of the law and the effect on the administration of justice of a retrospective application holding that the court has discretion to hear or to remand legal arguments raised for the first time on appeal