I agree that the "tried to self-isolate" is a bad statement.
On the first part, here's the issue I have with "feeling symptoms". I am not a doctor but I would think there is some period of time between when symptoms physiologically begin, and when you feel you're having symptoms.
Much smaller scale, but I'm getting over a bad case of bronchitis. It might have started on the day I drove to DC for a show two weeks ago, though I didn't start to feel sick until about 36 hours later. But the day I drove down I was going on very little sleep and tons of coffee and adrenalin, so maybe there were underlying symptoms, but I've also been in similar situations before without getting sick, so I didn't pay much attention at the time.
So I have to question the "no symptoms - zero transmission rate", because the latter is precise and the former is not.