The only way I can make sense of the knowledge that they come up with on the island involves time travel. The info they come up with is more than just what can be found on a paper trail. However if you have the ability to manipulate time, you can assign someone to follow Sawyer for the few days before the crash...... I know that the time travel theory is discounted by producers. But, it is the only way that I can make it work in my brain.