Associated Press TORONTO — The case against four physicians and a U.S. pharmaceutical company accused of failing to properly screen blood that infected thousands of Canadians with HIV and hepatitis was in jeopardy Monday after a key witness cast doubt on some evidence. After years of investigation, opening arguments were set to begin in the criminal trial of New Jersey-based Armour Pharmaceutical Co.; the former medical director of the Canadian Red Cross, Dr. Roger Perrault; two other Canadian doctors and one from the United States. But Superior Court Justice Mary Lou Benotto was told that a prosecution witness has questioned...