I kind of guessed that it was fiction.

Snarky comments aside, however, perhaps it seemed as if he'd been wandering around for longer and he actually wasn't. Or, you know, the author didn't check up on what the University of Minnesota has to say about how long someone can survive in freezing water before she wrote it.

We could also use the explanation 'It's Captain Kirk.' though. I mean, that man gets away with ALLOT.