NLRB's Burden-Shifting Test Governs Outburst Discipline — For Now

A federal appeals court has forced the National Labor Relations Board to keep applying its employer-friendly burden-shifting test when deciding whether companies can lawfully fire workers who curse at managers during protected concerted activity. The September development is the latest move in a long-running tug-of-war over when discipline for an outburst crosses into illegal retaliation under the National Labor Relations Act.

At stake is a compliance question every HR team with unionized or organizing-adjacent workers faces: can you terminate an employee for hostile, profane conduct when that same employee was also banding together with coworkers over pay, safety or working conditions? The answer currently depends on a three-part burden-shifting framework — and the Board has signaled it may tear that framework up in a future case.

What happened in Lion Elastomers?

The case involves an employer that claimed it didn't fire the worker for his union activity — he was a long-term, active union member — but because he was hostile and tried to create an intimidating environment during and after a safety meeting. The company's position was about conduct, not protected organizing.

In 2020, the NLRB first sided with the employee and ruled the firing violated the NLRA. To get there, the Board applied a "context-specific" test. That approach weighed factors including where the outburst happened, what it was about, how extreme it was, and whether the employer provoked it.

What did the General Motors case change?

Soon after the 2020 ruling, in a separate case called General Motors, the NLRB scrapped the context-specific rule and replaced it with a test that's less forgiving for employees. The shift matters because it reallocates who has to prove what.

Under the burden-shifting framework, the Board's prosecutor — the NLRB general counsel — must first show three things:

• The employee engaged in concerted activity.
• The employer knew about that activity.
• The employer had animus against the concerted activity.

If the general counsel clears that bar, the employer can still escape liability. It wins if it proves it would have taken the same action even if the employee hadn't been engaged in protected activity.

The General Motors Board explained its reasoning directly. It worried that context-specific standards "penalize employers for declining to tolerate abusive and potentially illegal conduct in the workplace." That concern mirrors what many employers say when they grapple with employee outbursts that occur alongside legitimate workplace complaints.

Why did the case come back in 2026?

Lion Elastomers was sent back to the NLRB to be redecided under the new burden-shifting test. The Board didn't apply it. Instead, it used the do-over to throw out the new test entirely and revert to its old context-specific approach.

The U.S. 5th Circuit Court of Appeals rebuked the NLRB for that move. The court ordered the Board to apply the General Motors burden-shifting test after all. So in 2026, the case sits before the NLRB once again — and this time the agency must work within the framework it earlier tried to abandon.

What should employers take from the ruling?

For now, the fired employee in Lion Elastomers — and everyone whose case follows — is subject to the burden-shifting standard. That gives employers more room to act, but it isn't a blank check. Companies can discipline workers who cross the line into abusive conduct even when those workers are engaged in protected union or group activity, provided they can carry their burden of proof.

The practical implication for HR: documentation of what the employer would have done absent the protected activity is now decisive. If you can't show the same discipline would have followed the conduct alone, the defense fails.

The fight isn't finished. The NLRB has signaled it may revisit the employer-friendly test in a future case — just not this one — meaning the standard governing outburst discipline could shift again depending on the Board's composition and docket.