Lawyer: A body of circumstantial evidence is like a rope, and each item of evidence is like a strand of that rope  Just as additional pieces of circumstantial evidence strengthen the body of evidence, adding strands to the rope strengthens the rope  And if one strand breaks, the rope is not broken nor is its strength much diminished
Thus, even if a few items of a body of circumstantial evidence are discredited, the overall body of evidence retains its basic strength
fails to consider the possibility that if many items in a body of circumstantial evidence were discredited, the overall body of evidence would be discredited