Cedars - "...her elders went straight into panic mode."
That's an easy one to explain.
She wasn't baptized, so they couldn't disfellowship her to insulate her from any other congregation members who might otherwise listen to what she had to say. The fact that she hadn't said anything to anyone else is irrelevent; from their POV, they couldn't take the chance, and had to nip it in the bud ASAP.
A rhetoric-laced platform freakout to stoke the fires of anti-"apostate" sentiment was therefore their only option, with the hope that the rest of the congo would put two and two together and conclude (correctly) that they were talking about her after she stopped coming...
...and thusly be too scared to speak to her on their own if they ever ran into her again (regardless of any "official" status she may or may not have had in the KH).
It was, in its own way, a knee-jerk reaction, but their only real recourse (not defending them, simply explaining).
It does set an interesting precedent, though...
...once you start labeling even non-members as "apostates", where does it end?