What is the test for applying an abuse of trust enhancement?

Because the propriety of applying an abuse of trust enhancement is a mixed question of fact and law, the ruling of the district court is reviewed de novo. United States v. Hill, 915 F.2d 502 (9th Cir.1990). The critical inquiry is determining whether a person is in a position of trust is "the extent to which the position provides the freedom to commit a difficult-to-detect wrong." Id. at 506. There are two factors to be considered: the inability of the trustor objectively and expediently to determine the trustee's honesty, and the ease with which the trustee's activities can be observed. Id.