As I presented in the post you quoted, that simply may not be how she contracted the disease!
Whether or not she came in contact with Duncan on his first visit in no way rules out the distinct possibility that she became contaminated by means of happening to contract the disease from touching materials touched by Duncan (walls, chairs, doorknobs, pens, examination tables, etc.) that weren't properly disinfected according to Ebola-prevention standards.
The CDC want's to blame what it can damage-control to prevent "panic".
The very real possibility of contamination via other materials .. or that she's not the only one currently carrying the virus spread all over the hospital from Duncan's first visit .. is not something over which the CDC realizes it can exercise damage-control to prevent "panic".
The CDC's line right now is all about damage-control, not about telling the truth.
The very fact that those knowing they're dealing with an Ebola patient would exercise the most extreme caution in protecting themselves when removing their protective gear simply attests to the likelihood that she didn't contract the disease via a mistake in that procedure .. and that she contracted it coincidentally as I presented in the post you quoted.