I think it is just people. I noticed all the date discrepancies, and not defending Casey, Cindy, and/or George at all, as they are primary family members, but as far as the friends, last night I started trying to come up with exact dates of the last time I saw this friend or that friend, and it is really hard to do. It would be one thing had Caylee's disappearance been reported right away, where a person could be like, "Oh, yeah, I saw her 3 days ago." but it had already been a month before these people were questioned.
People retrieve memories differently, and I know I have had people tell me stories where they go into "last Friday, no, maybe it was Thursday, no, wait, it was Friday..." Surely most of you in here have experienced the same thing.
Lanie