N.J. Admin. Code § 7:1J-9.15
Where there is only one known potentially responsible party, and that party fails to appear at the hearing without obtaining an adjournment thereof, and where neither the administrator nor other persons contest either the validity or amount of the claim presented to the Fund for payment, a decision may be made solely on the default of the potentially responsible party. In all other cases, a decision may not be made solely on the default of a party, and the board shall require the party who is present to submit such evidence as is deemed necessary to arbitrate the issues before the board, except that issues raised only by a defaulting party need not be addressed by the board, and the board's determination of all issues before it shall be binding as to the defaulting party.
N.J. Admin. Code § 7:1J-9.15