The Supreme Court this week sided with employees, ruling that workers can still sue if they suffer retaliation after making an oral, rather than written, complaint.

The ruling makes it even more important for companies to investigate all complaints of workplace discrimination or harassment, even if they seem informal. (Need help with a workplace anti-harassment policy? Click here. For a guide on handling employee complaints, click here.) 

Then factory worker Kevin Kasten was 24 years old when in 2006 he sued Saint-Gobain Performance Plastics for retaliation after he was fired for using a time clock incorrectly. Kasten, of Portage, Wisconsin, claimed his supervisors used this infraction as an excuse to fire him after he'd made repeated oral complaints about the clock's position. (Kasten had claimed that the company's positioning of the clock forced employees to punch in and out without getting credit for the time they spent putting on and taking off protective gear—a violation of the Fair Labor Standards Act.)

 "I stood up for my did Saint-Gobain," Kasten told his local newspaper, the Portage Daily Register. "They felt one way. I felt another." (Kasten, now 29, got the good news several hours late. The entrepreneur was too busy working at the grill at a restaurant he owns to take repeated phone calls from his lawyer.)

A Wisconsin federal judge ruled in favor of Saint-Gobain, and the 7th Circuit Court upheld the decision on appeal, concluding that federal labor law doesn't cover oral complaints. At least six other circuits have ruled that the laws do, however, include informal complaints to supervisors. So last March, the Supreme Court agreed to review the case. In a 6 to 2 vote (Justice Elena Kagan did not take part in the ruling), the court sided with Kasten in Kasten v. Saint-Gobain Performance Plastics Corp.

"Filings may more often be made in writing," Justice Stephen Breyer wrote for the majority. "But we are interested in the filing of 'any complaint.' So even if the word 'filed,' considered alone, might suggest a narrow interpretation limited to writings, the phrase 'any complaint' suggests a broad interpretation that would include an oral complaint."

Justice Antonin Scalia, in the minority, made it clear from the very start he would side with Saint-Gobain. "So you are filing your argument right now," Justice Antonin Scalia told Kasten's lawyer at oral arguments in October. "That is absurd." Justice Clarence Thomas voted with Scalia, who wrote in the minority opinion that complaints must be made to an official body such as the courts or some other government agency—that is, not even a written complaint to the company would suffice.

In the majority opinion, the Court decided a narrow interpretation of "filed any complaint"—in other words, not allowing oral complaints to be protected—would be bad for workers who find it difficult to put complaints in writing, particularly those who are illiterate, less educated, or overworked.

"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?" Breyer wrote. "President Franklin Roosevelt pointed out at the time that these were the workers most in need of the act's help."

Ruling out oral complaints also would impact workers by preventing federal agencies from receiving complaints through hotlines, interviews, and other verbal methods.

As for Kasten, he's hardly been consumed with the case. After he lost his job, he worked briefly at another, then managed to buy the Portage Cafe, a restaurant in his hometown. He also owns a snow removal business and recently became a co-owner of a frozen pizza business.

"My plate's full," he told the Register. "I've got to be doing something, always. I never know what life's going to throw at me."

Once he received the (delayed) good news, he took the day off to celebrate.