I dunno. Things have been moving pretty fast. While Miles was there and saw Claire wander off into the jungle, he's not a very forthright member of the team quite yet. Locke has been sworn to secrecy by the island. Which leaves Sawyer, who often shares info when it suits him, just like his stash, unless he gets emotionally involved. Which he has become, with Claire & Hurley, whom he has tried to protect. But, since losing Claire, he's been dashing from the battle for Othertown, to the beach, to the chopper, followed by an ocean swim, then a disorientating hike through the jungle as time shifted beneath his feet. Perhaps not conducive to a frank discussion of the whereabouts of Claire. Which means they can explore that mystery later, when things calm down again. Or, since she wandered out of the jungle once before, maybe they just think she'll do it again...