Great to get the official confirmation, but it was pretty obvious - if the thing was hard plastic, how could the head turn? It had to have some softness to be in any way positionable.
I think the issue people are having is not so much that it was hard, but the fact that it was "sculpted" so all snowies would have the same "faces" as opposed to some thin sheet material that would crumple as the head turned. It's clear that would have been almost impossible to achieve, and even if they did, the material would have been unlikely to last long.
All this being said, and based on the SDCC set-up, this figure is going to one of SSC's best figs.