Locke suggests to Sayid that the person who attacked him might be someone who has something to benefit from their situation (ie. being on the island), which really points straight at Locke himself since he has regained the use of his legs since crashing on the island, yet it isn’t until much later on that we actually find out that it was Locke who hit Sayid.
Sawyer’s letter
When Kate read out Sawyer’s letter it isn’t initially clear that he wrote it, it sounds more like it is referring to the storyline that is being played out in his flashback.
Sawyer’s position?
Sayid says “Sawyer’s position in the jungle” yet he didn’t know (as far as we are aware) that Kate was no longer there so why wouldn’t he say “Kate’s position” when it was Kate who was meant to set of the flare?