After hanging up the phone, Zhao Yu thought for a long time in the corner of the room. Interestingly, Han Kuan and Jiang Ke both spoke ill of each other behind each other's back.
When Zhao Yu was interrogating Jiang Ke, he firmly said that Han Kuan killed Hou Shengyun, a.k.a. Laogua. The reason was because he saw something change in Han Kuan's eyes after Laogua tore up Huan Kuan's manuscripts.
Later, it turned out that Jiang Ke was correct. Han Kuan was indeed the murderer. Because of that, Zhao Yu was deeply impressed with Jiang Ke's observation.
Apart from other cases, how Jiang Ke robbed the cigarette truck also convinced Zhao Yu that Jiang Ke was indeed a criminal wizard. If Zhao Yu hadn't foiled his plot, the police would have been fooled by him and possibly not caught him.