If that is true, then all Josie received was a flat text message - no demeanor, no body language, no facial expression, no tone of voice, none of those other clues - which the 13 year old with Treacy did receive for a period of time as she accompanied him. Further, the 13 year old directed Treacy to Josie, and then stood there and watched Treacy attack her, and to all reports, did nothing to attempt to stop him.
If we even dismiss everything that happened up until Treacy's fist met Josie's head the first time, at that point, the 13 year old knew exactly what he was doing. She watched him punch Josie until she fell down, she watched him bash Josie's head on the cement walk approximately 7 times, and then she watched him kick Josie's head with steel toed boots over and over and over.
She knew what he was doing, and she did nothing to stop him.