S2·E5 The Two Sides of Truth

In a court appearance Quincy comes up against his old professor, Dr. Herbert Stone, who is an expert witness for the defence. Stone comes up with a completely different view of the medical evidence to Quincy, which cause him to become confused and unsure of his own opinion. Because of this the prosecution loses. Later they appear to be on opposite sides again in another case. Stone refutes evidence that Quincy has found that shows that a rich businessman died in a fire. Quincy is upset when the Assistant DA points out that his old professor is now just selling his expertise to whoever will pay him.