One of the aspects of whistleblower law, is that someone can file a lawsuit claiming that another person has somehow fraudulently cheated a government out of money. It even applies to estate tax law.
Only a few states still have their own estate tax. For those that do, it often represents a small but important part of the state’s finances. It also gives wealthy people an incentive to move to states that do not have an estate tax.
In some cases, it has been alleged that a person falsely claimed to have been a resident of a no estate tax state, while actually living in a state with an estate tax. Such allegations are normally brought by state governments seeking to collect the estate tax they think they are owed.
That is not always the case as the Wills, Trusts & Estates Prof Blog reported in "Suit is Filed in NY's First Unsealed Qui Tam Estate Tax Case."
A whistleblower in New York claims that her former boss lied by claiming he was a resident of Florida, when he lived and worked in New York. She has filed a suit under whistleblower laws known as a qui tam lawsuit.
If the lawsuit results in money for the State of New York, then the whistleblower will be entitled to a share of that money. This is believed to be the first such case in New York that has not been filed under seal.
These suits are obviously rare. It shows that if you are going to try to deceive the government about your residency for estate tax purposes, you might not get away with it, if someone else knows about it.
Reference: Wills, Trusts & Estates Prof Blog (Jan. 25, 2018) "Suit is Filed in NY's First Unsealed Qui Tam Estate Tax Case."