From the Daily Mail article:
Sources involved in the decision told the Washington Post that CDC staunchly warned the State Department against transporting infected and uninfected people side-by-side, but were ultimately overruled.
...
The same article says the people who were infected were placed in bio-containment units, so they were not flown side by side. They did not violate the CDC’s warning.
Another article states is was just sheets of plastic....
it seems many people are trying to cover-up this stupid move by the State Department.
Coronavirus-infected Americans flown back to US on plane full of healthy people
“The two Boeing 747s had 18 seats cordoned off with 10-foot-high plastic on all sides and infectious disease doctors would be on board.”
That is how I understood how they flew them home. It’s not like they were in seats all over the plane. They were contained in an area off limits to other passengers.