- They look quite similar for one
- Because Sawyer went back to 1977, he would be about the right age to be Frank. Also because he was in 1977 it is would be expected that he pops up in the future.
- On Ajira 316, Frank sounded the same as Sawyer while talking to Jack
- It makes sense that Frank didn't fly Oceanic 815 because as Sawyer he knew it would crash, but he wouldn't of known about Ajira 316
- We also know the reasons for Charlotte, Miles and Faraday being on the island, but Franks are still unknown.
- Neither Sawyer or Frank trust Ben
- We see that Frank has a bookshelf above his TV in a flashback from the episode Confirmed Dead, this may show how Frank reads as does Sawyer