No, there is no meaningful recourse for those who fail the polygraph. One can appeal by sending a certified letter to U.S. Customs and Border Protection contesting the results, but the chances of being hired after a failed polygraph are essentially zero. Nonetheless, it is worthwhile to contest a false accusation of deception in writing, if only to document the fact that one does not accept the accusation.

Federal agencies share polygraph records, so your son's polygraph with CBP may become an issue if he ever applies for employment with another federal agency.