^I don't think the immunity ever applies if it can be proven you acted in a malicious manner toward someone. That's not what I'm talking about.
Look, here's the deal: I've been on the receiving end of several, similar accusations. In most cases, a disgruntled regulated entity will go straight to a politician, make up a sob story that usually involved accusations of personal grudges, incompetence, etc., and then myself and the other regulators get called in for a one-sided questioning or simple brow beating from the politician. There is no recourse for the regulator - it's always just our word against his, and there is no standard of proof when you're in a politician's office. If the politicians decide that they believe the person complaining about you (or if the person complaining about you has donated money to their campaign), they lean on your boss to fire you. You have absolutely no protection in this situation - a "firing" will be done in some way that leaves no ability for you to sue - in our case, they simply won't renew your yearly contract. You can't even sue for wrongful termination, because you weren't terminated, and you can't sue the original complainant because he is always careful enough to not put his accusations or request for your termination in writing, and the politician will NEVER take a regulator's side.
The "courts" are only a little different. Most regulatory court actions go before an administrative judge, which is often not exactly your most expereinced "judge", and not even in a court building. You get the same type of accusations in these "courts", but backed up by someone's lawyer who submits a long-winded pleading or whatever, full of cited case law (which WILL include this new ruling) justifying their position and justifying the legal reasons why the judge should find the regulators personally liable for having caused their poor, innocent client all this trouble. You get MAYBE a brief chance to answer "no, I did not ever say that" to the judge, but the opposing lawyers are usually good enough to know to keep you off the stand, or to at least keep those questions away from you. And these administrative judges are often in a hurry and not well versed in the technicailites of your profession, and usually write a final opinion that is loaded with factual errors and leaves you, the regulator, wrongly looking like an idiot. And your own agency lawyer is so busy that they rarely appeal, and NEVER request the judge to make technical/factual corrections on an opinion, for fear of opening it all back up again. Been there, done that.
So while I am sure that there are cases where regulators have stepped beyond their authority to wrongly punish someone, I also shudder at the thought of having another FALSE accusation brought against me by someone whose aim is to evade the law, and use me as the scapegoat to do so, and with this case prominently cited in their scheister lawyer's brief to the judge.
/end rant.