What's the difference between coercive and punitive incarceration?
As explained in the Executive Summary of Chelsea's first Grumbles Motion, there is an important distinction between a punitive sanction and one that is merely “coercive.” A person who is held in civil contempt may be confined (incarcerated) in order to coerce their compliance with the court’s order to testify before the grand jury, but they may not be “punished.”
If there is no coercive effect to their confinement, either because the grand jury has ended, or because there is no possible way they will be convinced to comply with the order to testify, then the confinement must be deemed punitive, and must end.
Simkin v. US establishes that incarcerated witnesses must be freed from confinement if conditions arise that makes purging their contempt impossible. This would include not only the conclusion of the grand jury investigation, but cases in which the witness can demonstrate that their convictions make them “non-coercible.”
Although the grand jury to which Chelsea has been subpoenaed has not yet ended, there is no possible coercive effect to her confinement, because nothing will ever convince her to testify. Therefore, the law suggests that her confinement is impermissibly punitive, and must end.