Expired licenses/IDs are almost uniformly rejected by the contract moat dragons and the TSA ID checkers. Stupid? Yes. But fighting that stupidity doesn't seem worth the effort.

No problem, however, since you are allowed to fly without ID. You just get the full SSSS treatment.

Is he even 18 years old? Reason I ask is that children under 18 don't have to show any ID to fly. Most people with Learner's Permits are usually 16 or 17.