Exactly, I couldn't agree more with you. The latest update about the newest patient states that when she boarded the flight her temperature was 99.5°F yet further in that same article this statement is made:
The risk of exposure to the passengers who were on the plane with Vinson is low, since she did not yet have symptoms, health officials said Wednesday.
Sounds to me like they need to get their stories straight because 99.5° is considered a minor fever to me and would be considered a symptom.