Disability Estoppel: The Intersection of Disability Benefits and Disability Discrimination Claims

It seems like an obvious conflict: an employee claims that she has a disability and is qualified and able to work at a job. She complains of discrimination because the employer terminated her because of her disability. Yet, in practically the same breath, she applies for disability benefits, insisting that she is unable to work and is therefore entitled to benefits. She should be estopped from one of those claims, right?