The two meanings of impossibility are different. The former means that it goes against facts and common sense. For example, 1+1=3 is "impossible", while the latter means that the commander is unbelievable. For example, Xiaoming told his mother that he got 1 points in the exam and her mother said "impossible"! These are the two meanings! Therefore, Conan's original words mean that excluding everything that goes against common sense and truth, the rest, no matter how incredible, is the truth!