The decision is available here and further documentation is available here. I would also like to refer to previous posts by fellow editors here and here. The US Supreme Court held that: “A federal court determining foreign law under Federal Rule of Civil Procedure 44.1 should accord respectful consideration to a foreign government’s submission, but the court is not bound to accord conclusive effect to the foreign government’s statements.”
In a nutshell, the US Supreme Court said that the weight to be given to foreign government statements depends on the circumstances of the case. In particular, it notes that “[t]he appropriate weight [a federal court determining foreign law should give to the views presented by a foreign government] in each case, however, will depend upon the circumstances; a federal court is neither bound to adopt the foreign government’s characterization nor required to ignore other relevant materials. No single formula or rule will fit all cases, but relevant considerations include the statement’s clarity, thoroughness, and support; its context and purpose; the transparency of the foreign legal system; the role and authority of the entity or official offering the statement; and the statement’s consistency with the foreign government’s past positions.”
One thing of note is that the US Supreme Court refers to Société Nationale Industrielle Aérospatiale v. United States Dist. Court for Southern Dist. of Iowa, 482 U. S. 522, which is a very important case in the context of the Hague Evidence Convention.