A substantively unreasonable sentence?

On April 25, 2011, the Court remanded a case for resentencing, and may have held, for only the second time, that the sentence imposed was substantively unreasonable.

In United States v. Worex, 09-5754 11a0264n.06, the defendant argued that her sentence was substantively unreasonable, due to the fact that the district court relied on uncharged allegations that were not proven by a preponderance of the evidence.  In remanding the case for resentencing, the court found that "before enhancing Worex’s sentence based upon her alleged involvement in the shootings, the district court was first required to make findings by a preponderance of evidence regarding this uncharged conduct. The district court did not do so, and its decision was therefore an abuse of discretion."

The Court remanded the case for resentencing on this basis.  It appears clear, from the Court's opinion, that this is a decision based upon substantive reasonableness standards.  There is no discussion in the opinion of a procedural reasonableness review.