I honestly think Sangwoo stabbed himself to make it look like his house was broken into, AND he was attacked.
I never thought of that and now I'm more convinced that happened o mg
I truly hope so
I mostly think that because it would be random and cliche as hell if bum just SUDDENLY jumped in.
Plus i only saw two pairs of feet, so... no bum, i assume.
I really don't think the cop would have been able to twist the knife around, honestly.
But another possible thing that could have happened is that the cop made that face because he was stabbed, and sangwoo made a face like "Shit, i missed my target" because he didn't stab something important and vital
I can't really say anything just cause Koogi is always unexpected but from what I see:
1. Sangwoo didn't stab the officer most likely. Judging from his face at the end, it's not a face he'd make if he did stab Seungbae
2. Either Sangoo got stabbed by Seongbae or Bum. Though considering that Seungbae never had a knife but a taser, it's least likely he stabbed Sangwoo but it's possible he may have gotten one when he was in the kitchen running away from Sangwoo
3. Bum got in the middle and got stabbed himself
But Koogi is always unpredictable and loves torturing us ヾ(❀╹◡╹)ﾉ~