[fintstone]

He is clearly guilty of theft, espionage, and flight to avoid prosecution. He might well not be convicted of treason, but there is every chance he would. Per the law:
"Whoever, owing allegiance to the United States, levies war against them or adheres to their enemies, giving them aid and comfort within the United States or elsewhere, is guilty of treason and shall suffer death, or shall be imprisoned not less than five years and fined under this title but not less than $10,000; and shall be incapable of holding any office under the United States"

"aid and comfort" is generally accepted to refer to any act that manifests a betrayal of allegiance to the United States, such as furnishing enemies with arms, troops, transportation, shelter, or classified information. If a subversive act has any tendency to weaken the power of the United States to attack or resist its enemies, aid and comfort has been given.

I believe that is the case.