I don't fault Soshnikov's positioning there. He's the weak side forward, and it's his job to watch the high slot if the other forwards are engaged on the strong side. There was a guy there, and Soshnikov was marking him. You don't vacate the high slot to take away the weak side point.
I don't fault Parayko, either. His first (and correct) instinct is to press out on the shooting lane towards Girard since nobody else was there. Dunn was already marking the only Colorado forward anywhere near the net. He subsequently (and probably correctly) released him to Parayko when Soderberg moved to that side of the net. When it was obvious that Girard was going to shoot and not attempt to move in, Parayko looked for a guy to tie up. Nothing Parayko could do to keep Soderberg from screening Allen at that point.
Allen was screened at the moment the shot was released, but he had the opportunity to set his angle and take his position while Girard was winding up completely unscreened. He knew the shot was coming, and he knew where it was coming from, and he had his chance to get set, so no excuses there. I guess he intentionally left room on the near side assuming he could glove anything over there, but he was screened at the last instant and he couldn't track it. Not sure I blame him for that, per se, but my understanding was that a goaltender should be positioned to cover the near side with his body and you lean to the far side if the shot heads that way. Maybe that teaching's changed since I was playing. I honestly don't know.
