Sort of a SWAG (and discussions with Wife MD). The drug treatment has to begin within the first 4 days based on Dr. Logan's work. All of his patients died when treatment was begun later. All of his patients were confirmed ebola. The 10 days is based on the "new ebola" course of infection.
Black Agnes has discussed the similarity between Epivir and Favipiravir, offered by the Japanese. Favipiravir was used to successfully treat the infection in a French nurse.
Doctor treats Ebola with HIV drug in Liberia — seemingly successfully
"Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases says that theoretically, Logan's approach has some merit. Lamivudine is a nucleocide analog, and other drugs in this class are being studied to treat Ebola."
Fauci was notified of this novel treatment back in September. I'll cut him just a little slack on this. The use of Epivir for Ebola is an off label treatment and forbidden by the FDA.