A West Virginia bank ran its asset value from $100 million to $1 billion over seven years by aggressively marketing subprime loans. The Office of the Comptroller of the Currency, a federal regulator, audited the bank and discovered that the books had been falsified for several years and that the bank was insolvent. The Comptroller closed the bank and brought criminal charges against its managers. The Comptroller fined Grant Thornton, the bank’s accounting firm, $300,000 for recklessly failing to meet generally accepted auditing standards during the years it audited the bank. The Comptroller claimed Thornton violated federal law by “participating in . . . unsafe and unsound banking practice.” Thornton appealed, contending that it was not involved in bank operations to that extent based on its audit function. What would be the key to determining if the accounting firm could be held liable for that violation of federal law? [Grant Thornton, LLP v. Office of the Comptroller of the Currency, 514 F.3d 1328 (D.C. Cir. 2008)]