The kidnapper wasn't actually a cleaner from ES; he was just disguised as one and was a severe mental patient who really enjoyed listening to Jian Chenxi's songs.
So he dressed up a bit, took a bomb into ES with the intention of kidnapping Jian Chenxi, but unexpectedly, he didn't run into Chenxi and due to a mix-up, he stormed into Ling Momo's office. Under the assault of so many people, he panicked and caused the incident we just saw.
The kidnapper, due to his mental illness and not causing any fatalities, could only be sent to a psychiatric hospital.
Thus, of all the people involved, the most unfortunate and the most frustrated was Ling Momo. She was the most innocent; the kidnapper wasn't even a fan of her music. The entire incident had nothing to do with her, yet she somehow became the central figure of the whole event.
It's just like the saying "lying down but still getting shot."
