What is the burden of proving that the issue at the heart of the collateral estoppel claim was decided in the previous proceeding?

A defendant bears the burden to show that "the issue whose relitigation he seeks to foreclose was actually decided in the first proceeding." Dowling v. United States, 493 U.S. 342, 350, 110 S.Ct. 668, 673, 107 L.Ed.2d 708 (1990). In making this determination, a court should "examine the record of a prior proceeding, taking into account the pleadings, evidence, charge, and other relevant matter, and conclude whether a rational jury could have grounded its verdict upon an issue other than that which the defendant seeks to foreclose from consideration." Ashe v. Swenson, 397 U.S. 436, 444, 90 S.Ct. 1189, 1194, 25 L.Ed.2d 469 (1970) (emphasis added) (internal quotations omitted). Moreover, "[t]he inquiry must be set in a practical frame and viewed with an eye to all the circumstances of the proceedings." Id. (internal quotations omitted). And the court should bear in mind that the rule of collateral estoppel is "not to be applied with the hypertechnical and archaic approach of a 19th century pleading book, but with realism and rationality." Id.