They still don’t know the actual point of contagiousness.
They say “when symptoms develop”, but that actually is a catch all phrase meaning “we aren’t sure. But we know it happens sometime around this point”.
And with the incubation period being 2 to 21 days, and it being found to linger in “ cleared” victims, it isn’t something to play with.
13% of the cases of Ebola, no fever present.