I was rewatching this episode last night. When Claire's house in NewOtherton is blown to pieces and she looks to be fine, Sawyer finds her rambling about Charlie. She is very disoriented as one would expect, but did she actually die and come back to life INFECTED, the same way Sayid did -- remember Sayid was totally disoriented at first and then he said he had NO FEELINGS. For Claire to abandon her own baby, she too would have to have NO FEELINGS.
She doesn't seem to be herself after this (most notably, her leaving her baby). But the biggest clue in my eyes is Miles. He seems puzzled and keeps staring at her, the same kind of way he kept looking at Sayid as if he knows something is wrong. I personally beleive that Miles reads peoples minds - not only the dead but the living as well. There are numerous examples for this i.e. Meet Kevin johnson, he immediately tells Michael that he is lying, that is not his name but don't worry 97% of the people on the boat are lying bout something. To Charlotte, "I m surprised you would leave after all you have gone through to find this Island" What do you mean, he replies and he says, hmmm what do I mean? Knows the exact circumstances of what happened between Kate and Sawyer when she returned to the temple, etc. etc. There are numberous examples - he reads peoples minds - living and dead.
Ok, so Miles is as concerned about Claire's state of mind, watchs her, studies her much like the way he watchs Sayid. He even asked to carry the baby, sensing something was wrong with her. She even comments bout how she was "seeing things" and was unsure about her reality as they were trekking through the Jungle. What are your thoughts?