If the tax or a part of the tax is paid or collected out of that part of the estate passing to or in possession of a person other than the executor in the capacity of executor, the person is entitled to a reimbursement out of a part of the estate still undistributed or by a just and equitable contribution by the person whose interest in the estate of the decedent would have been reduced if the tax had been paid before the distribution of the estate or whose interest in the estate is subject to an equal or prior liability for the payment of tax, debts, or other charges against the estate, it being the purpose and intent of this section that so far as is practical and unless otherwise directed by the will of the decedent, the tax shall be paid out of the estate before its distribution; but the department is not charged with enforcing contribution from a person.