At the end of the movie "The First Commandment", how did the brown mark on Shawn Yue's shirt come from?

The film does not give a clear conclusion, there are only two possibilities:

1, the officer accidentally spilled it on his body and looked at the remaining half cup of coffee, which seemed meaningless.

2. It is possible that the ghost passed from Yu to the Chief Executive. At that time, the Chief Executive was drinking coffee and spilled coffee on Yu.

Extended data creation background:

The Ten Commandments is a thriller directed by Kelvin Tong and starring Shawn Yue and Ekin Cheng. The film is set in "the city of tales of mystery", and the police receive supernatural phone calls, telling how the police handle five mysterious phone calls claiming that "there are some strange things in my house".

"Miscellaneous Affairs Office" is the department in charge of abnormal events, especially supernatural events in the police force. Li Guoqiang, Xinzha's brother, was transferred to this department after killing a serial killer who had been wanted for many years on duty patrol. He also met Sir Huang, an eccentric and alcoholic supervisor, who solemnly announced the first commandment of the "Sage Department": There are no ghosts in this world! But in fact, this is just a beautiful lie-not only did they encounter a lot of paranormal in the process of law enforcement, but even Sir Huang himself was caught in paranormal.