Justice Thomas’s First Decision to Assign a Supreme Court Majority Opinion?

Jonathan’s post about the lineup in today’s Dolan v. United States, in which the majority consisted of Thomas, Ginsburg, Breyer, Alito, and Sotomayor, suggests that this might have been the first time that Justice Thomas assigned a Supreme Court majority opinion (in this case, to Justice Breyer). That assignment decision is made by the senior Justice in the majority, treating the Chief as always having seniority. Am I mistaken on this?