In the case of DiFiore v. CSL Behring, LLC, the Third Circuit ruled for the first time that the more demanding “but for” causation standard applies to retaliation claims under the False Claims Act (“FCA”), rejecting the lower “motivating factor” (also commonly known as the “mixed-motive”) standard. The Third Circuit’s ruling is a welcome result, especially for employers who deal with the federal government and may, therefore, be exposed to FCA retaliation claims. But, employers need to be mindful that different causes of action have different causation standards. For example, the more stringent “but for” standard applied by the Third Circuit to FCA retaliation claims also applies in Title VII retaliation and ADEA cases, but the lower “mixed motive” standard applies in other cases, including “status based” Title VII and ADA discrimination claims. So, employers are left with a mishmash of different causation standards to consider when assessing risk around employment decisions and defending cases.

At trial, the District Court in DiFiore had instructed the jury to use the “but for” standard when analyzing whether the employer took adverse action against DiFiore because she blew the whistle on the company. The jury returned a verdict for the defendant employer.

In deciding that the District Court’s application of the “but for” standard was correct, the Third Circuit relied on the Supreme Court’s opinions in two cases, Gross v. FBL Financial Services, Inc. (an ADEA age discrimination case) and University of Texas Southwestern Medical Center v. Nassar (a Title VII retaliation case). In those cases – involving two different statutory contexts involving similar statutory language – the Court analyzed the applicable statute’s proscriptions against taking adverse action against an employee “because of” that employee’s membership in a protected class or engagement in protected activity. In both cases, the Court decided that “because of” means . . . well . . . because. That is, but for the protected activity (in the Title VII retaliation context) or but for the employee’s age (in the ADEA context), the employee would still be employed. In DiFiore, the Third Circuit concluded that the FCA’s proscription against retaliation “because of” the employee’s whistleblowing also served to establish a “but for” standard. Other circuits and district courts have also recently applied the “but for” standard to False Claims Act retaliation claims, either by explicitly ruling that it applies, or by assuming that it applies without deciding that issue.

At first blush, the reasoning applied by the Third Circuit in DiFiore would seem to support interpreting both the Dodd-Frank Act’s and Sarbanes-Oxley Act’s anti-retaliation provisions to require the same “but for” causation standard. After all, both of those statutes contain the very same “because of” language that appears in both Title VII and the ADEA, and which the Supreme Court has held in Gross andNasser typically equates to requiring proof of but-for causation.”

Some courts (such as the U.S. District Court for the Southern District of New York) agree that Dodd-Frank compels application of the “but for” causation for retaliation claims. See Lawrence v. Int’l Bus. Mach. Corp.

However, in Sarbanes-Oxley, notwithstanding that statute’s use of “because of,” Congress codified in the statute a much lower causation standard – “contributing factor” causation. A “contributing factor,” according to the case law, is any factor, which alone or in combination with other factors, tends to affect in any way the outcome of the decision. Therefore, under this forgiving standard, a plaintiff need only prove that her protected activity contributed to the decision to terminate her employment, even if there were other independent reasons for terminating her.

Plaintiffs necessarily face a greater challenge in order to satisfying the higher “but for” standard, especially when the employer can demonstrate that other factors contributed to its decision to take adverse action (e.g., documented disciplinary actions or inability to meet performance expectations).

While DiFiore is good news for employers in the Third Circuit, employers should be wary of the differing causation standards among the whistleblower statutes. With regard to False Claims Act retaliation claims (and probably also Dodd-Frank retaliation claims), plaintiffs must convincingly surmount an employer’s evidence that it acted for legitimate reasons. But for retaliation claims brought under Sarbanes-Oxley, an employer could be liable for retaliation if there’s even an inkling that it was motivated by an employee’s whistleblowing when it decided to terminate, demote, or otherwise take adverse action against her.