The reason why Zhao Yu asked this question wasn't because he had found anything, but was because he had a feeling that, as he had gotten a Kun hexagram earlier, the side quest that day might be interlinked with this main case.
Hence, practicing the theory of fake it till you make it, he decided to interrogate Cui Lizhu as such first! However, there was nothing to his hypothesis in the end.
When he brought up the murder case in the Changxin Longtai Pharmaceutical Factory, Cui Lizhu had only looked confused. She had never even heard of it! Actually, although the pharmaceutical factory was going through chaos internally, the news had yet to spread to the greater public.
Sigh!
Zhao Yu could tell from Cui Lizhu's perplexed reaction that she had nothing to do with the case! Thus, it would be impossible to find any clue regarding it from her.