Notwithstanding any other provision of law, the operator of a tow vehicle is not required to have an endorsement for towing a disabled vehicle that can be operated only by a person with an endorsement if the towing operation is the first move of the disabled vehicle and is performed as an emergency service or if the move is a subsequent move of an empty vehicle that requires a passenger endorsement or a school bus endorsement for operation. [1989 c.636 § 13a; 1991 c.185 § 4; 2003 c.14 § 471; 2005 c.649 § 4]