Determination unanimously annulled on the law and petition granted in accordance with the following Memorandum: At petitioner's Tier III prison disciplinary hearing, the Hearing Officer erred in refusing petitioner's request that a prison employee be called as a witness. Petitioner sought the employee's testimony in support of his defense that the charges against petitioner were filed as a retaliatory measure or as harassment concerning his participation on the Inmate Grievance Resolution Committee. That testimony was relevant to his defense and to the question of the veracity of the charges against him (see, Matter of Wilson v. Coughlin, 186 A.D.2d 1090; Matter of Martin v Coughlin, 90 A.D.2d 946). The determination is annulled, the petition is granted, and we direct respondent to expunge all references to this incident from petitioner's record.