There's no reason why this is outrageously unfair. An external consultant is only held to an advisory standard because they are external - they are not party to the detailed nuances that management may have inadvertently or deliberately concealed.
It's outrageously unfair because when you hire an advisor you typically know so little about their domain of expertise you have no idea what questions to ask them.
So you have no effective oversight over the quality - or otherwise - of their work.
Of course you can hire another professional to double check the advice of the first professional, but that soon gets expensive, you're pretty much guaranteed some angry muttering, and you're still not guaranteed a reasonable outcome.
It's a remarkable fact that consumers have more rights when buying a toaster than when hiring an accountant or lawyer - and the toaster is going to be more reliable, and much less expensive to run.
