I can't see that this is a bug, unless I'm missing something?!
See my response here
The highlightGraphic is being added on top of the southCarolinaCounties layer thus masking it, so it is the highlightGraphic that will get the click, unless you expect the click to penetrate through to any 'lower' layers?
For me this is totally expected behaviour, for it to work any other way would be very odd!
Thanks for your post Luke! By removing my highlighted graphic, I can execute both the "click" & "mouse-over" events on a single point graphic.