Unless the artist (whose job should be designing the armor/scenery etc.) is also directly coding that information, no, that's an issue with the coding and how the helm interacts with its surroundings.
Eeeeer no, not at all. Clipping is an issue that relates most of the time with how the character is animated and how the influences are "painted" on the mesh, that is the weights that the bone structure has an how it applies it to the mesh, and how hard it applies it : and this is tipically an art issue.
Most of the time it's a rigging issue, sometimes it's an animation issue, sometimes a mesh issue, and yes sometimes the coding of the physics can make stuff clip BUT this is because the art department made a mistake somewhere and didn't test properly.
That said, I do think the art department is doing a very good job all accross the board, the only thing i'm bothered with is the management that don't give them enough time allowance to fix those UNLESS it's for a cartel item model...