Is disclosure of ex parte communications between a judge and juror necessary?

Disclosure of ex parte communications between a judge and juror is generally necessary when the communication relates to an aspect of the trial. Rushen v. Spain, 464 U.S. 114, 119 (1983). In the absence of disclosure, the prejudicial effect "can normally be determined by a post-trial hearing. Id. "[T]he factual findings arising out of the state courts' post-trial hearings are entitled to a presumption of correctness." 28 U.S.C. 2254(d); Rushen, 464 U.S. at 120; Sumner v. Mata, 449 U.S. 539, 547 (1981).