Forensic Heroes Error 1

The Errors in Forensic Heroes
"They are the Forensic Heroes, I am the Critic" - tvbsquare

If you haven't figure out who killed the three family members in the first case, please do not read this post. I recommend you to watch it first, at least till episode 3.

The case: three family members murdered.
The suspect: Ka Nin Ngo
What happened: Ka Nin killed his family members, and then sticks a knife in the middle of the bookshelf, and then he tries to hurt himself so that no one knows he killed his family. However, when he tried to hurt himself, he slipped; as a result, he hurt himself so badly that he almost died. After he hurt himself, he still has the strength to clean the weapon, and put it back to the kitchen table.

Error 1: Look at the picture below, the knife is at a 90 degree angle. After Ka Nin slipped, he hurt himself so bad, how did he manage to get the knife out?



Error 2: If he managed to get it out, his blood will be everywhere (on the bookshelf, on the floor, on his cloths). If he hurt himself that bad, he can not even stand and walk around. How did he manage to clean the knife and put it back to the kitchen table without leaving any blood?!