It all could've been a very different story had Claudio Marchisio not been on hand to steer home what was retroactively deemed—rightly—to be Alessandro Matri's third-minute goal.
Neither the far-side assistant, nor the goal-line referee flagged for the original goal, despite the fact that the ball had quite clearly crossed the entire line. Their failure only serves to underscore a larger point: The goal-line referee is an utter waste of precious refereeing resources.
Alas, neither referee's mistake is terribly surprising. It turns out the goal-line referee—whose very existence is motivated by the desire to accurately determine whether a goal has been scored—is, like the assistant, positioned in a terrible place to make that determination.
Since the goal-line referee stands right on the goal line, his view of the area just inside the goal is partially obstructed by the goalpost! The goalpost isn't just a line, after all, but an object with actual thickness. As a result, the goal-line referee cannot necessarily see the whole of the ball cross the goal line even if it does. This basic fact of trigonometry seems to have been lost on whoever at UEFA decided where to put the new refs. (Think back to England vs. Ukraine at Euro 2012 for another high-profile failure. These aren't coincidences.)
But that's not all.
Since he's looking straight on at the goalpost, this referee will actually lose sight of the ball for a split second any time it crosses the goal line as it goes behind the post. Unfortunately, that's precisely the moment when it is most important to be tracking the ball's path.
Vision scientists—aided by common sense—have known for quite some time that it's more difficult to track the trajectory of an occluded object than one that we can see.
If the placement of the goal-line referee on the goal line seems insane, it's because it is. A much better positioning would put the referee closer to the goal—instead of a good six yards away—and slightly behind the goal line, so that he could actually see the inside of the goal in its entirety.
An even better role for the goal-line referee might be to not exist at all, or to be upstairs in a booth somewhere. After all, while so few games are decided on close goal-line calls, offside calls are routinely and consistently blown. Though these missed calls aren't as salient, since they're called back before a goal can be scored, the sum of their effect in the final reckoning is surely greater.
You've probably already forgotten the dubious offside decision against Marchisio in the 61st minute on a play reminiscent of his eventual 77th-minute goal. Shouldn't there be extra referees devoted to that instead?