Section 350-91-004 - CONDUCT OF PROCEEDINGS004.01 Any proceeding to invalidate an assessor's certificate initiated by the Department of Revenue shall be conducted pursuant to Practice and Procedure Regulations, Chapter 90, governing contested cases.004.02 Burden of Proof 004.02A The burden of proof in a proceeding to invalidate an assessor's certificate initiated by the Department of Revenue shall be on the Department of Revenue to show, by a preponderance of evidence, that the holder of the assessor's certificate has willfully failed to perform his or her duties under the applicable constitutional or statutory provisions, or the rules, regulations or instructions promulgated by the Tax Commissioner and Property Tax Administrator. For the purposes of these regulations, preponderance of the evidence shall mean evidence which, as a whole, shows that the facts or set of facts sought to be proved is more probable than not.004.02B In any proceeding to invalidate an assessor's certificate, if the holder of the assessor's certificate seeks to assert that he or she was justified in willfully failing to perform duties required of the holder of an assessor's certificate, such an assertion shall be treated as an affirmative defense. In such instances, the holder of the assessor's certificate shall have the burden of proof to show, by a preponderance of the evidence, that compliance with the state law or rule or regulation alleged by the Department of Revenue to have been violated would lead to a significant decline in the quality of assessments, or a significant decline in the uniformity and proportionality of assessments.350 Neb. Admin. Code, ch. 91, § 004