Well I saw a thread on reddit today http://imgur.com/a/6ixSH#0

concerning a spot in the blue side bush which can be exploited to give full vision without being seen.

After some testing with various champions I've determined that players from either team can exploit this location, however not all champions can. This leads me to believe that the issue is with the model size of certain champions.

Most AD carries I tested with worked.
Malphite can use the spot, but Blitz and Alistar seem to be too fat.

It takes a bit of careful placement to get certain champions in the correct spot, while others have a more forgiving area for invisibility.

Technically speaking, it would take a fair bit of coordination to glean an advantage from this exploit, but it could happen. If you push your lane (purple side) and have your appropriately sized jungler (works confirmed with skarner and malphite...scary.) you can position yourself in bush. The enemy can actually walk just barely outside the range of skarner ultimate before they get vision of him, which means you can really catch people off guard with this.

Have yet to test other bushes. Looking into it later tonight when I'm back from work.

Cheers.

instead of the bush being "an area" which when you are in it exempts you from bush blocking for that particular bush (a simpler method even) the way riot handles it is drawing a line, if it hits a bush edge, further objects in a bush beyond that edge are obscured. Thanks for the bug report nonetheless.

-Best of luck, Google

This is working as intended as far as bushes go. Eg, the tri bushes, if you stand in one part that is not actually visible to some other parts (like standing on the far edge of the tribush, wtih the other person standing on the far edge of the tri bush) you actually can't see the other person, and it will act as if you are outside of the bush.

Works the same with wards, saplings, all those little things, blah blah. its just the way bushes work.