Was it a goal? The Argentines thought so. A computer-assisted replay on German television made it appear so. But the referee had already called it as a save, and the game went on.
The issue was again thrown into relief on Sunday, when a French shot appeared to have gone over South Korea's goal line, but was not called as a goal. The game ultimately finished in a 1-1 tie.
It's ambiguities like these, debated endlessly by bloggers and sports fans, that a new generation of soccer technology aims to avoid. But despite promising recent technology tests, this year's World Cup in Germany still lacks any high-tech help that might settle questions of contested goals or other controversial calls.
"The technology we're looking for, we can't find yet," said George Cumming, a former Head of Refereeing for the Federation Internationale de Football Association (FIFA), soccer's international governing body. "We've tried. The technology has developed, but I think it hasn't solved this problem."
The resistance to new technology highlights a cultural gulf between soccer and most professional sports in the United States, which have long used instant replay and other high-tech aids to help referees make the right call.
American football has used video replay systems to check referees' calls for more than half a decade. Basketball referees use replay systems to make sure players are shooting within the time allotted by the shot clock. But soccer officials and fans worldwide are adamant that the smooth flow of their game not be interrupted--even if that means sacrificing perfect accuracy.
Many deem video playback systems, which must be monitored by someone off-field, an unacceptable infringement on the referee's traditionally complete control over the game's play. A purist camp even points to referees' human frailty as an integral part of the game.
"What referees see is what they feel from the game, what experience tells them is happening, and what their fatigue level allows them to see, just like the players," said Chuck Fleischer, a longtime U.S.-based referee, and an editor at AskTheRef.com, a popular soccer Web site. "The human eye is not as quick as a computer, but the human mind can pick up all the nuances, all the smells, the looks on people's faces, and make a decision."
This skepticism doesn't mean that soccer's powers-that-be aren't looking for a good high-tech assistant, however.
As long as a decade ago, FIFA officials approached researchers at the University of Glasgow in Scotland for help. They came up with nothing that could satisfy the league's stringent requirements, however. Later, an independent Italian inventor approached them with his own idea for a goal-identifying chip inside the ball. Officials tested it, and found it wanting.
A ball, a chip--a goal?
The latest and most promising prospect has been a "smartball" loaded with an RFID chip, jointly developed by German companies Cairos Technologies and the Fraunhofer Institute for Integrated Circuits, an engineering research and software development company, along with the Adidas athletic clothing and shoe company.
The companies' technology uses a network of receivers around the field designed to track the ball's precise position in real time--including exactly when it has fully passed the goal line. That information would be relayed in less than a second to a watch-like device worn by the referee.
Officials were initially hopeful that the system could be used at this year's World Cup. But after tests late last year in a Peruvian tournament, FIFA announced that the system was not yet ready for top tournament use. Neither the companies nor FIFA provided details on exactly what the problems were.
"From the technological side, there are still some things that needed to be cleared up," Anne Putz, a spokeswoman for Adidas in Germany, said this week.
Cumming, however, said the system had several problems. Balls that were shot over the goal, but landed on the net, were counted as goals. Shot information could take several seconds to reach referees. And perhaps worst of all, the presence of several balls on the field simultaneously--as when a ball boy threw an extra ball on the field slightly early--could crash the system, the former top ref said.
A spokesman for Cairos Technologies said further tests would be scheduled after the close of the World Cup.
Can the camera be fooled?
A rival Italian technology that would use "high-performance digital cameras" is also in the early experimental stages. FIFA officials gave their go-ahead last March but have not yet provided any details on the technology, and have not yet scheduled any official tests.
Details are scarce on precisely what the Italian system would entail. But the Italian football association has been funding research into such a system for several years, and published papers outline some of the difficulties.
An automatic camera-based system that doesn't rely on a separate observer off-field has several difficulties, researchers have written. Genuine image recognition is perhaps the trickiest part--any system must be able to distinguish a ball crossing the goal line from a hand, foot or stray pigeon, for example.
These and other hurdles mean that, as the teams winnow down to just two next month, the referees and their assistants will still be relying only on the evidence of their own, fallible senses. But until a team loses a game because of a bad call, don't expect to hear many complaints from soccer die-hards.
"You have to look at soccer as being a human game," Cumming said. "It's the greatest game, the people's game. And people make mistakes. If you sanitize football too much, you lose the beauty of the game."