I've taken a closer look and I'm pretty sure what I've found backs up my theory. Here's what I did: I charted each pitch, keeping track of what I thought the pitch would be based on whether or not he "tapped the glove," so to speak. Out of 104 pitches, 35 were either out of the stretch -- where I don't think he tipped pitches at all -- leaving us with 69 pitches. Of those 69, I correctly "guessed" on 54 of them, so I was right at a 78% rate which I think backs up my theory. All fifteen times I was wrong I guessed off-speed (I didn't see a glove-tap) and he threw a fastball. Since he can throw a fastball without doing the glove-tap; it shouldn't be too hard to eliminate that altogether (the times I was wrong seemed to bunch together, for whatever that's worth). Here's some video of what I mean (apologies for the not-great quality, but I think you'll be able to see it). Keep a close eye on his left hand just before he breaks his hands...
First, the most obvious example I saw of him doing the glove tap on a fastball:
Now a more subtle glove-tap fastball:
And a fastball with no glove-tap:
A breaking ball (no tap, obviously):
And lastly, here's a four-pitch sequence to Brandon Hicks in the second inning. Can you guess the pitches as he delivers them?
So, do you guys think there's anything to it? Obviously Gwinnett either didn't pick up on it or the stuff was just too good that any adjustments they made didn't matter, as he fanned 13 in eight innings.