Ziparo v. CSX Transportation

Circuit 2Nov 25, 2025

Split Score

SplitScore: 60/100

Case Summary

Disposition

Vacated

The Second Circuit vacated summary judgment for CSX in a whistle-blower case under the Federal Railroad Safety Act. Relying on the Supreme Court’s 2024 decision in Murray v. UBS Securities, the panel held that an FRSA plaintiff need not prove the employer’s retaliatory intent; temporal proximity and other circumstantial evidence can satisfy the ‘contributing-factor’ test. Finding disputes of fact on both a retaliatory hostile-work-environment theory and on whether protected activity contributed to Ziparo’s firing, the court remanded for trial.

View Full Opinion Document (PDF)

Circuit Split Identified

Legal Issue

Whether a plaintiff in a Federal Railroad Safety Act (FRSA) whistle-blower suit must prove the employer’s retaliatory intent/animus to satisfy the statute’s “contributing-factor” causation element.

Circuit Positions

Circuit 2(this circuit)Circuit 3Circuit 9

Contributing-factor standard is broad; employee need not prove employer’s retaliatory intent. Temporal proximity alone can suffice.

Circuit 7Circuit 8

Employee must present evidence of employer’s retaliatory motive/animus; temporal proximity by itself is not enough.

Conflict Summary

The circuits disagree on whether the FRSA’s AIR-21 burden-shifting framework requires the employee to introduce evidence of the employer’s retaliatory motive. The Third and Ninth Circuits (and now the Second Circuit in this opinion) hold that no proof of employer intent is needed—the protected activity need only be a contributing factor, which may be shown by circumstantial evidence such as temporal proximity. The Seventh and Eighth Circuits continue to require some evidence of retaliatory intent or animus as part of the employee’s prima-facie case.

Parties & Counsel

Parties

Appellant:Cody Ziparo
Appellee:CSX Transportation, Inc.

Legal Counsel

Appellant:P. Matthew Darby – Darby Law Group, LLC
Appellee:Joseph C. Devine – Baker & Hostetler LLP; Susan Roney – Nixon Peabody LLP