It's not a checkmate. Here's the game, and I'm not sure how he did:
Everyones opinion on the Stonewall attack

From Torre experts, who generally only enter the setup against KID players because the shape after 1.d4 Nf6 2.Nf3 g6 3.Bg5 Bg7 4.Nbd2 d6 5.e4 or 5.c3 and 6.e4 gives White some chances for opening advantage.
I played this setup myself today in a USCF-rated tournament game against a player rated about 1750 and won in 18 moves.
the Torre against g6 is good, but its not bad against e6 either.
nice game btw

From Torre experts, who generally only enter the setup against KID players because the shape after 1.d4 Nf6 2.Nf3 g6 3.Bg5 Bg7 4.Nbd2 d6 5.e4 or 5.c3 and 6.e4 gives White some chances for opening advantage.
I used to play the Torre as White as well; let me just throw this in.
After 4...d6 there is no reason not to play 5.e4 straight away.
After 4...O-O it is best that White play 5.c3 waiting for Black to commit the d pawn, since White has been unable to show advantage against 5.e4 d5!

The Stonewall doesn't work as a universal weapon against any Black defense, but it is possible to use as White. Winning attacks usually consist of Nf3-e5 followed by a pawn storm.
If 1.d4 Nf6, it is best to play something else. Maybe 2.Nc3 as Black usually responds 2...d5 and now 3.Bg5 is the Veresov where White can, on occasion, play e2-e3 and f2-f4, creating a type of Stonewall with the bishop outside.
If 1.d4 d5 2.e3 Bf5, it is best to play 3.c4 with the idea of a quick Qb3, to exploit the early bishop move.
If 1.d4 d5 2.e3 Nf6 3.Bd3, White has ruled out the quick ..Bf5 and can start thinking about setting up a Stonewall, either with f4 next or Nbd2 first (to overprotect e4, discourage a quick ..Ne4)

I'm new to this site and am around a 1350 to 1450 rated player as of now. I'm curious what everyones opinion is on the stonewall attack opening. Ive been using it with pretty good success. I'm finding that the move order changes a lot based on what Black does.
If it works for you keep on using it but start learning openings the way the great hypermodern GM Reti recommended in his classic book Masters of the Chessboard: learn open games first and by open games he means Double KP Openings whenever possible. Next focus on semi-open games and finally closed games.
I can't think of any GMs who play it routinely or even occasionally but instead of pointing out why I'll let you figure this out on your own - but here's one hint: if you don't know what "holes" are in your position it's time to start learning basic principles of opening theory and positional play - and by "positional play" I mean how to identify weaknesses in your position (and your opponents), how to avoid them and how to exploit them - I'm not talking about trying to play like Petrosian or Karpov.
Click on these links for more info on the Stonewall you should find useful and on general opening principles. GOOD LUCK!
http://www.nationmaster.com/encyclopedia/Stonewall-Attack
http://www.onlinechesslessons.net/2011/11/01/the-stonewall-attack-chess-opening/

The Stonewall doesn't work as a universal weapon against any Black defense, but it is possible to use as White. Winning attacks usually consist of Nf3-e5 followed by a pawn storm.
If 1.d4 Nf6, it is best to play something else. Maybe 2.Nc3 as Black usually responds 2...d5 and now 3.Bg5 is the Veresov where White can, on occasion, play e2-e3 and f2-f4, creating a type of Stonewall with the bishop outside.
If 1.d4 d5 2.e3 Bf5, it is best to play 3.c4 with the idea of a quick Qb3, to exploit the early bishop move.
If 1.d4 d5 2.e3 Nf6 3.Bd3, White has ruled out the quick ..Bf5 and can start thinking about setting up a Stonewall, either with f4 next or Nbd2 first (to overprotect e4, discourage a quick ..Ne4)
The only issue is that after 1.d4 d5 2.c4 c6 3.e3, 3...Bf5! is a reliable equalizer for Black (or at least a damn good try) because White has no way to exploit the early Bishop development. Black will not have serious problems defending b7 as he might after 1.d4 d5 2.c4 c6 3.Nc3 Nf6 4.e3 Bf5?! 5.cxd5 cxd5 6.Qb3 where 6...Bc8 might be the most reasonable. One main difference is that the c1-Bishop is hanging so White doesn't have time to take d5. Another difference is that if White does try to play Nc3 Black has time for ...e6.

It's not a checkmate. Here's the game, and I'm not sure how he did:
In comment #25 where you show your game vs J.C. (1750). I have to say J.C. is a moron. The Idiotic play starts at 8... a6?! and gets worse as the game goes along.
From Torre experts, who generally only enter the setup against KID players because the shape after 1.d4 Nf6 2.Nf3 g6 3.Bg5 Bg7 4.Nbd2 d6 5.e4 or 5.c3 and 6.e4 gives White some chances for opening advantage.
I played this setup myself today in a USCF-rated tournament game against a player rated about 1750 and won in 18 moves.
That had to be a resign, if that was a checkmate i think would speak for all of us as i want to see that game. Open bar during games? How did this opponent do in the rest of tournament?