This seems a bit unnecessary, there are elegant solutions already being built into mobile browsers which is by far the best place to address issues like this.
I kind of assumed mobile browsers might already be doing this -- 'smudging' clicks a few pixels towards the nearest clickable region, whenever they land someplace neutral.<p>Still, if/when they don't, this seems helpful. In particular, if the HN up/down triangles had this, biased in the direction opposite each other, there'd be fewer mistaken votes on touch screens.