You may have to ask an employee to accompany you to a hearing or appeal meeting. You cannot force an employee to participate, but in some cases they may be summoned, if not by you, by an attorney or government entity handling the situation. If the employee is scheduled to appear during normal work hours, he is to be paid his usual wages in addition to mileage to travel to and from the hearing site if he drives himself. If it is a court case, he will have been summoned to appear. For a hearing, he may want to send a written, notarized statement in lieu of attending, but this is not effective because the judge cannot cross-examine or ask questions of a piece of paper. The most effective witness you can have is a real person.
Do not tell an employee what to say during a hearing; however, you can collaborate together to discuss the reason for the hearing and review the facts. Thank the employee for his cooperation — he may find it difficult to testify if the claimant is a person that he works with or socializes with outside of the workplace.
An employee may be asked to attend a hearing after witnessing behavior that has led to employment termination or he may have information about an employee with an alleged workers' compensation injury who is trying to defraud the system. No employer wants to get employees involved in issues like these, but it may make the difference between winning or losing a claim.