Darcy Jensen, a module team builder for Amgen Inc., filed a workers’ comp claim as a result of health problems that she believed stemmed from exposure to laboratory animals. Several months later, the company discovered mold in the building where Jensen had worked. Jensen eventually sued Amgen under an exception to the workers’ compensation system permitting employees to bypass workers’ comp and sue for damages where the employee’s injury was aggravated by the employer’s fraudulent concealment of the injury and its connection to the employment. But a California Court of Appeal has now dismissed the lawsuit, ruling that the fraudulent concealment exception didn’t apply. The court pointed out that Jensen knew of her symptoms before anyone at Amgen did. And, to sue for fraudulent concealment, it’s not sufficient to allege that the employer “should have” known about the injury—rather, there must be evidence that the employer actually knew about the injury before it was reported and took steps to conceal its existence, which wasn’t the situation here.