Specifically,i think it is,it does connects the other paths of the story itself,but i think you missed another thing,well remembered all the dreams,nightmares of Walter?
The part where there's Herbert laughing while killing/stabbing Lars,well lars path, I don't know what day it is but anyway, before it shows,Walter is at their school and there's Mark there,Anders,Coach gil, and Parker,as the story goes on,their faces are blurred with the red mist,and everything they say is blaming Walter from what he did which we don't know exactly what happens.
This is so hard,i can't go on more, that's all from me