Considering shoulder breakage on subsequent releases has sharply dropped, I would say that the chance of the -1D having shoulder problems is pretty low unless you fling it around by its arm mid-transformation.  Who knows, maybe that's what people have done to the other releases that have only had one or two breaks just so they could be in with the in crowd?   
You know, sort of a "Uh oh, my Yamato product isn't breaking on it's own!  I better break something subtly enough that I can blame it on design, engineering, materials or QC, so that way I can bellyache about it on the forums!" 
Vostok 7