TLDR: When you commit a crime for an employer, you and the employer are responsible and must both receive the consequences. Even if you signed a contract saying you're not liable -- doesn't matter; you can't choose to be "not liable". When you commit not-crime for an employer, the consequences (the payment/income from that work) are given entirely to the employer; they are treated as if they were 100% responsible/liable. Somehow, this time, you can separate yourself from liability with a contract.
The argument is: Either liability is totally inseparable from a person or it is totally separable. We can't have "its inseparable but only if the person is committing a crime".