Yougor Jallah will be a good test of that. She took her step father's temperature at least twice, propped him up in bed, took his BP, gave him hot tea. After he was taken to the hospital she came back and disinfected the apartment. If she did all that unprotected and doesn't get it, then the CDC might have a point. It is day 7 for incubation for her if she has it.
Either way, you can’t plot a trend with only one data point. But you are correct that we will find out—the crew pressure washing the vomit off the sidewalk had no visible PPE, and at least one person was walking a short distance away in the parking lot (maybe 20-25 ft.). They are candidates as well.