He’s quarantining himself in Canada? Why didn’t he think to do that in LIBERIA???!!!
Because he arrived home in Canada, symptom-free, before his colleague became sick in Liberia.
All the evidence is that Ebola is NOT TRANSMISSIBLE until you have symptoms of it, and even then it doesn’t transmit very easily if you stay away from the ill person.
It’s a virus, so it could mutate, but that’s the current state of things.