What is the test for obstructing justice in the context of the obstruction of justice statute?

Neither side challenges the district court's jury instructions, which required the Government to prove, inter alia, that "the defendant had knowledge that his actions were likely to affect [an] official proceeding," and which defined an "official proceeding" as "a proceeding before a court, judge, or federal agency." The instructions further provided that "[t]he proceeding may be civil or criminal" and that "a federal grand jury proceeding is an official proceeding." However, "a criminal investigation is not an 'official proceeding' under the obstruction of justice statute." United States v. Ermoian, 752 F.3d 1165, 1172 (9th Cir. 2013) (emphasis added). Although the statute confirms that "an official proceeding need not be pending or about to be instituted at the time of the offense," 18 U.S.C. 1512(f)(1), the Government agrees that, to show the requisite nexus, it had to establish that an official proceeding was at least foreseeable at the time the obstructive actions occurred. The statute states, however, that there is no requirement to show that the defendant knew that the foreseeable official proceeding would be a federal proceeding. Id. 1512(g)(1).