All payment of benefits, expenses of administration, and any other expenses arising hereunder, may be paid by the pension board out of the trust fund, unless otherwise paid by the county. Such expenses shall include any expenses incident to the functioning of the pension board, or any person or persons retained or appointed by any fiduciary incident to the exercise of their duties under the plan, including, but not limited to, fees of accountants, counsel, investment managers, and other specialists and their agents, and other costs of administering the plan. Until paid, the expenses shall constitute a liability of the system.