Oh fr? I thought that was actually Woo Jin
This is only what I predict. I mean, maybe Woo Jin puts Junghwi & the other guy under hypnosis spell. Because of my reading experiences, the presence of other guy suddenly in the picture always foreshadowing something. I may be wrong though but convince of my intuition.
I thought it was Woo-Jin because of the deliberate placement of the backpack holding the door. But your theory is also a possibility #－.－)
I thought it was Woo Jin too but all three of them has black bags. And Woo Jin's shirt sleeves are folded during group meeting (so the tshirts may have long sleeves but Woo Jin fold it) but during the rape, the shirt sleeve is not folded (the other guy may have this tshirt under his blue hoodie). But arghhhhh my head hurts. Yet, it fun tho with the guessing hahah.
Woo Jin is so EVIL to involve Jung Hwi & make someone rape him. (I think that other guy fuck Jung Hwi under Woo Jin's spell). Disgusting Woo Jin.