A man, who lost his left leg due to a doctor’s alleged negligence, and his wife have received a $3.1 million jury verdict — a record high for a leg-amputation case in Winnebago County. Donald Johnson, a retired Loves Park police lieutenant, was admitted to Rockford Memorial Hospital on Aug. 10, 2010, complaining of dizziness, weakness and suspected upper gastrointestinal bleeding. Johnson, a longtime cigarette smoker, had a history of peripheral vascular disease that partially or completely blocked the …