Can a physician be convicted of a violation of 21 U.S.C. §841, post-Ruan, when that physician's conduct in prescribing the controlled substance was both subjectively and objectively reasonable as evidenced by the fact that the recipient of the prescription had been prescribed that very same controlled substance by other physicians both before and after her encounter with this physician?

Can a physician be convicted of a violation of 21 U.S.C. §841, post-Ruan, when that physician’s conduct in prescribing the controlled substance was both subjectively and objectively reasonable as evidenced by the fact that the recipient of the prescription had been prescribed that very same controlled substance by other physicians both before and after her encounter with this physician? Is the Fourth Circuit improperly applying its harmless error standard in assessing Ruan error?