Ill. Admin. Code tit. 26, § 125.195
If the Hearing Officer in an adjudicatory hearing determines that a witness is hostile or unwilling, the witness may be examined by the party calling the witness as if under cross-examination. The party calling a witness, upon a showing that he or she called the witness in good faith and is surprised by the witness' testimony, may impeach the witness by proof of prior inconsistent statements.
(Source: Amended at 35 Ill. Reg. 2351, effective February 4, 2011)