If someone was on the outside of Vollering on that corner, they'd also have been "pushed into the barriers." The rider in 2nd wheel going into the corner doesn't lose Vollering's wheel throughout the bend. Are you saying she should just get out of the way because Kasha is half wheeling her? It's a tactic as old as time to have a domestique behind on the climb and let a gap go. That's why rivals don't generally let a domestique sit between them and whoever they want to stick to. It was hardly Sagan on Cav.
The point has been missed, I think. Gery leads Vollering up to the corner to attack at the base of the climb that starts there. Nobody is outside Vollering on the corner, and she's the front rider so can pick her line. As Gery drops back from her lead out she's on the inside on the corner and instead of leaving her attacking leader to get a gap she comes across to take her wheel briefly, pushing Kasia out wide. Gery went from being in front of Vollering, who had Kasia on her wheel, to being behind her, pushing Kasia off it.
I don't think it's worth commisaires having a look or anything, but it's pretty unsporting and would have put Kasia in a ditch (barriers were gone by then) if she hadn't stopped up