When I use the warp tool to straighten a horizon I'm left with big bands of damaged pixels throughout the image. This issue happens in both Photoshop & Lightroom. This issue is new, I've used this tool much more drastically in the past & quite regularly. It first occurred about a month ago. (The transform tool is the easiest way for me to display this issue...but it also occurs when I use Curves layers, or blend multiple exposures using luminosity masks, sharpening, noise reduction etc...)
Shot on a canon 5diii in RAW and edited as a RAW file on Mac OSx 10.10.5
Camera Raw, Photoshop, and Lightroom are all up to date.
Here are some screenshots:
PHOTOSHOP SCREENSHOT (note the banding in the sky)
LIGHTROOM (just to show that it is also plaguing my images with this banding)
I've seen something similar before (moire-like pattern), and it turned out to be the lens correction profile. Try to turn lens correction off and compare.
It is the lens correction profile, as well as the transform tool. Unfortunately I would like to not abandoned these tools all together as they do prove to be useful.