There were literally dozens of methods to prove it. Get Sam to write something and put it in a safe that will only be opened after 50 years. Have him collect clues for a cold case. It is evident that they cannot get him to go home because people who are working on the QL project are not very bright.How is that proof that god exists? And who can that be shown to? Even the oversight committee were unable to see proof that Sam was even in the past, let alone anything supernatural.
