http://bugs.winehq.org/show_bug.cgi?id=33446
--- Comment #5 from Sam Edwards CFSworks@gmail.com 2013-04-24 02:54:28 CDT --- The bug is caused by overriding the material (in Source) to something else (e.g. the glow effect) - this can be demonstrated by "r_drawothermodels 2", which causes some models to mess up, but not others.
The affected models all have something in common: They have bones. This means that the problem is actually improper hardware skinning when a material override is active. Setting "mat_softwareskin 1" stops the distortion from happening (but does cause other artifacts).