No fact officially stated by an officer in respect of a matter about which he is by law required to make a statement in writing, either in the form of a certificate, return or otherwise, shall be called in question, except in a direct proceeding against the officer or his sureties, or upon the allegation of fraud in the party benefited thereby or mistake on the part of the officer.
Official acts may be questioned collaterally, when
KRS § 61.060, under GENERAL PROVISIONS AS TO OFFICES AND OFFICERS -- SOCIAL SECURITY FOR PUBLIC EMPLOYEES -- EMPLOYEES RETIREMENT SYSTEM.
KRS § 61.060