Homicide or sudden death?

This morning, a dead man was found near a monsoon drain along Pujut 5C in Miri. From a distance, I saw a crowd, ambulance and police cars. Being nosy, I went to "investigate" and become an unqualified "crime scene investigator".

The man seem to have slipped from the top. The drain wall is vertical. So, his legs was "below" and body at the top of the drain.

His belt was loosen and he was clashing a plastic bag which was found ...

... to contain a small mobile phone.

There is a little trail just beyond the place the body was found. So the police went in and found a sleeved short knife, a pair of  slipper and an empty Carlsberg beer tin.

The police kept all the finding in the plastic bag, a mobile phone and wallet .
At site, no blood was found. Robbery seems to be ruled out as the wallet was still there. However, his belt was loosen! Why? I suspected that he went in to the trail to release himself during the night. When he returned, he wasn't careful, slipped into the steep drain and suffered a heart attack and died. His eyes were still open.
I just realise that this does not tally as to why the slipper was left behind. So my other theory was that as he was inside the trail, he could have saw something or bitten by a poisonous snake and ran for his life, dropping his slipper, slipped and fell into the drain, heart attack and died.

Ok, lets wait for the report from the pathologist. Then we will know the actual cause of death.

By the way, this dead person looks very familiar! Sorry, I can't publish his face.

Update: See Hua Newspaper reported today: The man just stabbed his ex-wife the day before. The police think that he could have died of hypothermia. I thought that if this is the case, then the man should be in fetus position and the eyes closed because he will first went into coma. I may be wrong!