Malcolm didn't know the woman he swapped with during the Great Shift. He didn't know her name, where she lived, or who any of her friends were. She had no purse or ID with her at the time of the incident. The only things he knew about her were what he was able to figure out from her body alone. For instance, he knew she was flexible...very flexible. It was certainly one of the many joys he took from being in this body.