What specific examples of magical thinking in Casey's behavior are you thinking about?
IMO the witness didn't make it very clear what parts of Casey's behavior were supposed to be magical thinking. Her anecdotes didn't apply to ICA's situation as far as I could see.
(If it's true that she knows nothing about her case it is possibly quite an expected outcome. Most people have experienced being way off base when they're talking about something they know nothing about.)
And she should be off base. That is, her anecdotes should only reflect examples of, in this case, magical thinking, or other behaviors as they might relate to grieving and/or trauma. In other words, as a "
topical" expert witness, her job was to inform on behaviors as they relate to grief and trauma. It is then up to the trial atty, in this case, the defense team, to explain to the jury how her testimony might relate to KC's behavior. The primary idea here is to open the door to plausible alternatives wrt KC behavior.
Wrt to your question about magical thinking. Imho, the defense could argue that KC was not lying. That she instead, constructed a make-believe world that included leaving her child with the make-believe nanny while she went to her make-believe job. And that this was obviously a case of magical thinking bc she even tried to take the investigators to her make-believe job... to show them where she worked. I would proffer that they would then support this argument by noting her flat affect and how it demonstrates she is entrenched in Elisabeth Kübler-Ross' denial stage of grieving. I would finish it off with the proposal that KC learned this behavior, and then proceed to note how the Anthony's did not even realize she was pregnant, as an example of how this sort of thinking was common in that household.
That said, while I, personally, think KC straight up lied, my opinion does not matter. What matters is whether the jury buys the alternative explanation as plausible, and if so, whether that is enough to cast reasonable doubt on the state's case. I think it's a *very* long shot. However, I think it's the best shot they have. Moreover, iirc, there are at least three jurors, who, through their professional experience, would have encountered individuals who engaged in magical thinking, and in fact, exhibited flat affect in the face of extreme loss. So, they might be banking on them finding the alternative argument plausible. After all, this "
expert witness" was called in at the last minute.