After reading that people have had either success or failure in getting rid of the bleed/making it worse by either pinching the corner or attaching the set to a wall mount, I'm convinced the light bleed has to do with the way this television is assembled. It might be so thin that the frame needs to be evenly attached to the panel for a more uniform screen.
While you shouldn't be able to touch the corners hard enough to affect backlight uniformity, this is perhaps an issue with all edge-lit LED TVs that opt for a thinner design (most of them). Some are just worse than others. You even see tablets with this issue from time to time.
I'm wondering if stepping up to the LM9600 (which has full local LED dimming) would make this a non-issue. Even so, if you were able to find that particular model, you'd be spending about $2,000 for the 47 inch model (from what I've seen). Considering I spent $850 for this set, have the backlight bleed in only the top right corner, and the fact that this TV is an amazing overall performer with that one exception, I'm still very happy with it. It has one of the lowest input lags of all modern TVs, colors are generally pretty accurate, smooth motion, etc. It really is a nice TV for that price.
And my main thing is, no matter what you purchase, there will always be issues in this price range. No TV is perfect. A lot of people are complaining about IR issues with the 2012 Panasonic plasma models, for instance. And I'm sure that the first couple of generations of OLEDs will have major issues as well. It's all relative.
55" Samsung KS8500/55" Sony XBR810C/PS4 Pro/NVIDIA Shield TV