Ben Counter
Not to be confused with a device for keeping tracks of Bens.
Ben Counter is a novellist for the Black Library and winner of a Golden Demon award.
Some of his books are filled with fail, other Awesome. Of particular note is his series of novels about the Grey Knights.
According to regulars at his FLHS, he spends a disproportionate amount of time torturing himself for the fact he might be writing fluff violations he isn't aware of.
In fact, games get interrupted by sudden bouts of angst along the lines of "Wait a minute! You mean your forces can do <something I didn't know about and fluff for which I may have unwittingly transgressed in my book>?"
Those that would admit to using 1d4chan wonder if there might some award named after him, which would represent everything that Matt Ward does not. (The TG Award for Adequacy?)
(If anyone's reading this, maybe they can come up with something suitable; we'll run up a real physical trophy, present it to him out of gratitude, and we can thereafter award it to other people in the community who actually care about the game and the game world.)
It's worth noting that not only is his Grey Knights series FAR more definitive in how the Knights operate than the codex written by Ward, but he's also done a really fantastic job of making daemons sound genuinely horrifying to deal with. Also of note is his unbelievably poetic description of the Warp in his book Battle of the Abyss, a book that also pulls a Graham McNeill with its portrayal of the Ultramarines. Also includes probably the last in-canon good-guy of the Thousand Sons.
He is not Sandy Mitchell.