The trainee doctor sparked outrage last month after she implied she had deliberately injured a man who mocked her by missing his vein during a blood draw.
She now claims she did so accidentally, and says a more qualified medical professional made the second blood draw attempt in line with existing procedures.
Wake Forest said an investigation found Del Rosario’s claims on Twitter did not reflect the incident, adding she had followed the guidelines correctly.
They did not comment further on how they had established the facts of the case.
Meanwhile, a statement by the student hinted she would be back working after she had ‘reflected’ on her ‘social media use as a professional’.
The school was condemned for its slowness to respond to the scandal, and has yet to comment on the liability issues it could face if it does let Del Rosario loose again.