Not at all, a pre symptomatic person could easily shed enough virus to infect everyone within a few meters of them. Japan and Korea both have published papers showing contagion at 4 meters in a still air environment such as indoors or in a bus in the Japanese paper. There was an inside reception after the outside ceremony where there was hugging and hand shakes and close contacts it’s absolutely probable that one of those who later showed symptoms was already shedding virus at that inside event.
Right, and because the incubation period from infection to definite symptoms can vary so much, and because initial symptoms can vary so much, with COVID-19, I agree: Most likely, one of the people we are thinking of as being infected at the ACB ceremony actually was the spreader.
My own experience with colds bears this out somewhat: I’ve had colds that went from me feeling fine to off my feet and in bed in a day, others seem to gradually ramp up over several days, and many might start out as just the slightest hoarseness after talking too much, or being in a lot of dry air, seem to go away a few or several days, and then come roaring back over a week later.
When did I become contagious? Darn good question.
Regardless if I am Mo’ Nature or an evil Chinese virologist (Mo’ Nature is infinitely more capable), if I am designing an ideal virus to afflict humans, high shedding before noticeable symptoms occur is tops on my list of “features desired”.
Indeed, the transition from pre-symptomatic to symptomatic is not a matter of black and white. Feeling a bit fatigued, for example: Is it the chicken, the egg, or some of both?
I’d also point out (again) to many on FR that most of the group at the ACB ceremony are people likely to be more easily infected than an average American.