It became airborne only in the sense that the Liberian-American victim was flying in an airplane when he became symptomatic.
This particular Ebola is not as deadly as other strains. It is only 60% fatal... Ebola can be 90% fatal.
In the event that Ebola becomes more easily transmissible, its fatality will probably drop. (Lethality and transmissibility have an inverse relationship.) One species of Ebola, Ebola Reston, may be transmitted through the air, but it is not known to cause symptomatic disease in humans. It has been found in pigs and monkeys.
Flight time from Liberia to Nigeria is 2 1/2 hours. He had to have known he was infected before he boarded. Just saying.