Actually, the CDC investigation found that Duncan was contagious, and the nurses were using PPE incorrectly when they arrived on Sept. 30. Frieden said CDC investigators found that on Sept. 30, the day of Duncan's Ebola diagnosis, healthcare workers were donning "three or four" layers of protective gloves and gowns, thinking that would increase protection from the virus. But such measures, Frieden warned, may have increased infection risk. There were many issues with the PPE, not just the one quoted here. I do not want to quote too much from the LA Times, but the full article has a lot more information.
You do note that the head of the CDC claimed that nurses did not have to even have ANY head or foot coverings to treat Ebola patients, right??? He said all of this on a Megan Kelly interview show. Megan Kelley was quite incredulous, as were ALL of America!