(Snipped to address specific point)
Patsy says they were up in JonBenet's underwear drawer.
So if the case were PDI do you not think Patsy would have gone to the bother of making sure there were size-12's in JonBenet's underwear drawer?
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Someone would have removed the package to distance themselves from the crime; someone who was also staging with PR; someone who had done so without telling PR perhaps; someone who had hired his own lawyer.
Realistically, the underwear package was grabbed from her drawer, then staged, then collected with all the other evidence (i.e. the other end of the paintbrush that was never recovered, the latex gloves that no doubt were used during this phase, etc.) and stashed/hidden until they were disposed. What would the point have been to put the package back into the drawer after using a pair for the staging? What if blood got on the package, etc.? Regardless, there would have been no point in keeping the package and/or the remaining pairs of underwear; it just would have been an unnecessary risk, particularly when they were disposing of items anyway.