I agree completely. This was caused by a faulty pv. Most commercially made VV pv's, that I know of, come with protection to prevent this from happening.
Indeed. The ONLY way this happens is if the device is continuously firing. The atomizer can't draw electricity by itself.
So either your firing button was pushed in accidentally, your switch went bad, or something conductive came into contact with your switch that caused the circuit to open and not close.