Who is plotting against whom?

"Okay, I don't take it to heart. The investigation is over, you are not a suspect, goodbye."Frank Fang turned around and was about to leave.
"Lord Fang, please don't investigate Frank Fang... He has nothing to do with this matter." Lu Qi said behind him.
Frank Fang turned around, looked at Lu Qi's sweaty face, and said with a smile: "Don't worry, why should I cause trouble for myself?"
This sentence sounds like it is troublesome and it is better to have less trouble than more.
But...