If Jiang Yao could think of that, then the person in charge of the interrogation would think of the same thing as well. Therefore, they were not in a hurry to make that point. They would have an answer once they managed to question everyone from the hospital.
Lu Xingzhi did not ask for Jiang Yao's presence for her to see Madam Chai. She was also one of her victims—Madam Chai did point a gun at her, so she was there to make a statement so that they could charge her for that crime as well.
Officer Chen took Jiang Yao's statement; he was gentle with her because he knew that she was Lu Xingzhi's wife. He asked a few important questions and then ended the interview quickly.