Judge Murphy of the Sixth Circuit Court of Appeals did not seem too happy with the argument a defendant made in her appeal of a Medicare fraud conviction. The defendant claimed that the government violated the Federal Rules of Evidence and thus violated her Due Process rights. However, the judge held that a violation of a statute or rule does not necessarily equate to a constitutional violation:
I think that violations of the rules of evidence are on a sliding scale relative to a correlation of a constitutional violation. For example, on one end, a violation of hearsay will directly implicate the Sixth Amendment (See Crawford). On the other end, a violation of 401/402 (relevance) is much more in the discretion of the trial court.
United States v. Manzano, No. 18-2318, 2019 WL 5561389 (6th Cir. Oct. 29, 2019)