That's true, but it's difficult to envision any scenario where a lawyer supplies the exact advice needed to trigger a reversal outside of threats/suing/arbitration. Maybe if you get a good one I guess, but that is a gamble on its own.

A lawyer supplying helpful information like "Ok, this expulsion was triggered by the Department of Admin, which is overseen by John Smith, who has the power to reverse this decision. Schedule a meeting with him or find office hours to plead your case. I shouldn't get involved outright because it will escalate your situation and be received poorly." is less likely than "I can write a threatening letter and we'll see where it goes". A hammer hammers.