Well, I also don't understand fully since I read the raw, the dude was kind of drunk then fell down to the ground while brought a box of chicken in plastic bag, the ML saw him and trying to help but the drunk dude being drunk threw the chicken to ML, the chicken box opened up and the chicken of red sauces got the ML clothes, the drunk dude getting up and say something while walking towards the ML then going straight to the ML and the ML hold him from falling , that's how the red sauce also got the drunk dude when ML caught him before passed out, it was the very moment MC saw them and misunderstood, the ML also shocked and dropped the dude to the floor when he saw MC before the MC running away

It was actually chicken with hot or red sauce