No, they still owe every dime of payroll taxes (FICA, Medicaid etc.) and they still owe sales taxes on every taxable item they purchase. And direct or indirect property tax payments. They just simply get back more in Federal benefits than they pay in Federal income taxes.
The same exact thing can be said for thousands of corn, soybean, wheat, rice, and cotton farmers in this country who get back more in Federal farm subsidies than they pay in Federal taxes and wind up every year with a big check from the government. Or any of millions of other American citizens and corporations who receive more in government benefits than they pay in taxes. Including large numbers of extremely wealthy people as well.
None of this is even new. From Catch-22, written in the 1950s:
“Major Major's father was a sober God-fearing man whose idea of a good joke was to lie about his age. He was a long-limbed farmer, a God-fearing, freedom-loving, law-abiding rugged individualist who held that federal aid to anyone but farmers was creeping socialism. He advocated thrift and hard work and disapproved of loose women who turned him down. His specialty was alfalfa, and he made a good thing out of not growing any. The government paid him well for every bushel of alfalfa he did not grow. The more alfalfa he did not grow, the more money the government gave him, and he spent every penny he didn't earn on new land to increase the amount of alfalfa he did not produce. Major Major's father worked without rest at not growing alfalfa. On long winter evenings he remained indoors and did not mend harness, and he sprang out of bed at the crack of noon every day just to make certain that the chores would not be done. He invested in land wisely and soon was not growing more alfalfa than any other man in the county. Neighbors sought him out for advice on all subjects, for he had made much money and was therefore wise. “As ye sow, so shall ye reap,” he counseled one and all, and everyone said, “Amen.”