If LE thinks Jayme made the call, they would not have come to that conclusion until many hours later, or longer, since no one spoke to the dispatcher and identified themselves. Also, although a cursory search of the house would reveal what looks like a teenager's bedroom, without knowing the family and who lived in the house, it would take some time (apparently 2 hours) to establish that a) a teenager lived there, and b) said teenager is missing. There are many pieces that had to be put together to come to the few conclusions that we know about. IMO.