In what circumstances will a federal court strike down a jury's erroneous jury instructions?

In this case, even if the jury instructions were erroneous, any error by the district court did not affect the defendants' substantial rights. In order to satisfy this prong of the test, defendants must "establish that the probability of a different result is sufficient to undermine confidence in the outcome of the proceeding. " Id. (quoting United States v. Dominguez Benitez , 542 U.S. 74, 83, 124 S.Ct. 2333, 159 L.Ed.2d 157 (2004) ). Defendants have not met that burden here. Had the jury been correctly instructed that it was required to find that the drug quantities at issue were associated with conduct "in furtherance of the jointly undertaken criminal activity," it seems highly unlikely that a different result would have been reached.