Why would Congress want to limit the enforcement scheme's effectiveness by inhibiting use of the Act's complaint procedure by those who would find it difficult to reduce their complaints to writing, particularly illiterate, less educated, or overworked workers? ... To limit the scope of the antiretaliation provision to the filing of written complaints would also take needed flexibility from those charged with the Act's enforcement. It could prevent Government agencies from using hotlines, interviews, and other oral methods of receiving complaints. And insofar as the antiretaliation provision covers complaints made to employers [...], it would discourage the use of desirable informal workplace grievance procedures to secure compliance with the Act.

Saint-Gobain initially claimed that, because the anti-retaliation provision applies only to complaints filed with the government, it is exempt from suit since Kasten's complaints were directed to a private employer. The Supreme Court refused to address this argument because, though Saint-Gobain raised and ultimately lost this argument in the lower courts, the company did not address the issue in its response to Kasten's petition for certiorari. Justices Scalia and Thomas disagreed with the majority, suggesting that the court has previously permitted parties to defend a judgment on grounds not raised in the brief in opposition when doing so is "predicate to an intelligent resolution of the question presented, and therefore fairly included therein." In an earlier suit brought by Kasten, the US District Court for the Western District of Wisconsin [official website] held [opinion, PDF] that Saint-Gobain violated the FLSA by placing timeclocks in a location that prevented workers from receiving credit for time they spent dressing in work-related protective gear.