I can see the argument for slowing down the game.
Say that ball didn't actually go in, and we had the TV replay stuff. The game stops, we look at the reply, and the ball isn't in. Germany could have gone on a counter attack and scored from the Neuer 'save'.

My question is this:
A technology similar to hawk eye, how quick is this? Can you use it live or with minimal lag (say less than 1 second).
I don't think technology should be used for decisions such as fouls/dives. As there are grey areas to what is a foul and what isn't, and there are too many occasions where we can watch a reply several times and still not be sure.
But for if a ball is over the line or not, if the tech is quick enough, can they not just put it on the screen saying 'GOAL!"?
And this doesn't just need to be goal line, it should be for the by and touch lines, as if the ball is out, it is out - no judgement needed.