I get that LE was swamped with people calling to report their dreams, visions and theories. I am sure as soon as KW said the word "psychic" that Cain tuned out.
HOWEVER, even the size 6 Disney dress featured on Nancy Grace got sent in for testing. So did numerous items found by searchers. Unfortunately, it seems Cain was afraid of looking paranoid and unmanly by calling out other cops to collect evidence found because of somebody's mother's vision. We will never know whether or not there was evidence that would have led to the area being declared a crime scene months ago.
I think Cain was negligent. I don't think his motives were nefarious.
However, since KW shared the news of his find, the bag disappearing, to me, looks like there is a possibility that someone purposefully removed evidence that might have led to Caylee being found months earlier.
To me, that points toward the possibility of individuals trying to protect Casey because they know she's guilty and that a dead Caylee might prove it. And nothing else.
IMO