Yes, it certainly would be recommended to have a lawyer defend you in a DMV hearing; it wouldn’t be wise to go without one.
While the administrative court is able to do the proceeding of a DMV refusal hearing on police paper work, it is possible that that officer who arrested you may show up. If the police officer comes to the hearing, your attorney will have the opportunity to cross examine him or her. The prosecutors would not want the police officer to come to court, because in the New York State no advocate must represent the police officer in court. The prosecutors know that the testimony given by the officer in court can have serious implications in court.
If you have an experienced lawyer he may help you summon the officer in court, and corner him to receive a favorable testimony that can seriously dent the prosecutor’s case. The testimony by the officer can not only be used to recover your license but it can also be used in your DUI criminal case in court.
Without a lawyer, you may not only lose your license but you may be charged with a ‘consciousness of guilt’ in court by losing the refusal hearing.