Most of the posters are missing the point. Stafford was signalling for everyone to line up and he was going to perform a spike. His offensive live didn't even block (except for the center). Nobody knew he was going to sneak it. If the D-Line had played like normal, it would have been a dead Stafford.
But, if they went and Stafford did indeed spike the ball, it would have been a huge mark against Dallas.
Personally, I have no problem. I don't even have a problem with the victory formation being "attacked" in certain scenarios. Look at KC the week before this one. They kneeled with a very small lead. If the snap was muffed by Smith, and Houston recovered, they had a chance. Yet, they just sat back and let KC win the game. In the event of blowouts, I understand, but in some cases, you shouldn't stop playing until time is out.