Pilots in the US need to pass a biennial flight review with a few hours of ground… or add a rating instead. It’s possible he was operating under BasicMed so he may not have needed a recent medical.
And even with BasicMed, your primary doctor has to certify that you are fit to fly. It's less rigorous than a full FAA flight medical by design, but it's not a rubber stamp. (You're also limited to smaller aircraft that are unlikely to do much damage on the ground.)
I wouldn’t be surprised if he was in very good mental+physical condition though. The crash might have nothing to do with age.