If the calibrations are incorrect, it could indicate people are above the legal driving limit of 0.08 BAC even if they weren't, or below the legal limit when they were actually above it.
Clark's attorney, Conrad Vincent, said in December he thought O'Neill's decision was fair. He did not respond for comment Tuesday.
Michigan State Police began the investigation into Clark and fellow technician David John in January 2020, after a review found inconsistencies in paperwork submitted from Alpena County.
Clark is charged with two counts of forgery of a public record, two counts of uttering and publishing and two counts of using of a computer to commit a crime.