I also remember Sloan seeing what she didn’t like on a page of Nicole’s report. And I believe that she changed two tests taken at different times. I could be wrong, but I thought they repeated the blood tests for Nicole’s extra special doctor checkup arranged by EJ.
That still doesn’t mean anything. The writers can always decide to say some rando changed to results first in a double switch. It wouldn’t be the first time. Maybe Clyde, Ava, Vivian, or someone else who wanted to punish EJ got to the results, then came Sloan.