Haw. Code R. § 16-23-87
In the event of the failure of any member, through insolvency or otherwise, to pay promptly its portion of any loss or expense, after the JUP has made written demand upon it to pay the loss or expense, the commissioner shall take appropriate action. If the loss or expense remains unpaid beyond a reasonable period, all of the other motor vehicle insurance insurers, upon notification by the commissioner shall promptly pay their respective pro rata shares, based upon the predetermined participation ratios. Members which have made contributions shall have the right to recovery thereafter against the member in default, provided, that the commissioner may enter into an agreement with the member in default, or with its legal representative, upon an amount which shall constitute a full settlement of all of the obligations of the member to the remaining members.
Haw. Code R. § 16-23-87