I don’t see any reason that they would wait. Usually it’s just the team running up. The Vicki g got the spike within about 7 seconds. And they waitress to line up.
They mention this on every broadcast. They say playing so much man coverage means the defenders are not looking at the backfield but are tracking their guy. They say with zone most of the coverage is looking at the QB and can react sooner.
That was the correct call. Make them throw the ball then get to the line. Remember that Dallas got a huge return right before halftime that cost 3 points.