Back when Liang Gan stabbed Mo Mo, she'd already suspected Xie Shiyu. However, midway into the investigation, many clues were lost.
These lost clues were due to Gu Huanan's interference.
In addition to Gu Huanan sending people to kill Xia Yumo at the hospital, naturally, Qiaoxu shifted her investigation focus to Gu Huanan.
During the time when Xia Yumo was unconscious, Xie Shiyu's actions were like those of a noble green tea, apart from trying to "run into" Gu Junhang in the hospital and wanting to play the love script of long time. She couldn't find any other actions.
Moreover, her security personnel at the hospital were watching her closely. Neither Xie Shiyu nor her people had a chance to approach Xia Yumo, so Qiaoxu was relieved.
It wasn't until Director Meng told her that Xiayumo had been poisoned for half a year that she began reinvestigating Xie Shiyu.
