IRS Commissioner John Koskinen said Wednesday the two unnamed employees who destroyed thousands of emails belonging to Lois Lerner, former head of the tax-exempt unit, kept their jobs at the agency.

During his impeachment hearing before the House Judiciary Committee, Koskinen said the two officials had committed an “honest mistake” by wiping 422 back-up tapes believed to contain Lerner’s emails in 2014. The emails had been requested under a congressional subpoena during the investigation into the Internal Revenue Service’s targeting of conservative groups.