Thomas Fitzgerald never knew what hit him. One minute he was riding home from his night-shift job and stopping his bike at Broad and South Streets to watch a mob scene that appeared to be getting out of control. The next, he told a Philadelphia judge yesterday, he was waking up four days later from a medically induced coma, with his hearing impaired and his memory scrambled. Two other witnesses yesterday helped piece together Fitzgerald's lost minutes as they described how, about 11:30 p.m. May 30, the 53-year-old bicyclist was set upon by eight young males, beaten, and left unconscious...