AUSTIN — The 17-year-old accused of hitting a child and fleeing the scene pleaded not guilty in court Monday. The juvenile driver was charged with two counts of criminal vehicular operation causing harm after allegedly running into 11-year-old Tristen Ringlen in the 1300 block of Fourth Avenue Southeast on May 27. According to the 17-year-old's charging documents, he returned to the scene and claimed to be a witness who chased after the suspect …