#1) The doctors first test negative, second test (72 hours later) , was positive - he could have been shedding virus in that 72 hour period. Testing is known to have false negatives.
#2) "he had not had a single patient survive Ebola up to the point he was infected. Not a single one. - that reaffirms him shedding virus, since statistics previously show a median 30 - 40% recovery rate.
#3) he is absolutely certain that .. they were so very strict with their practices, procedures, and PPE." - much of that medical protective gear which already was needed to be upgraded.
Just a note about the PPE that Brantly and his team were using. It was all being provided for by Samaritan’s Purse, so they did not have to depend on what would be available at the African hospitals or clinics. I would think that they had the best possible PPE that Samaritan’s Purse could provide for them.