When Dustin Johnson tried to cut the corner on the par-4 third hole with a driver, his ball had other ideas and headed near the 16th green. The ball sailed into a heavily wooded area behind the green. The area is marked as a lateral water hazard.
The forward observer with the group did not see the ball come down and many spectators and volunteers in the area heard but did not see the ball rattling around in the trees. The referee with the group, USGA President Jim Hyler, knew they would be searching for the ball. Hyler used all the information available to him in the search, including NBC, the USGA's television broadcast partner. Unfortunately, video could not help because cameras lost sight of the ball when it came over the TV towers. Per the Lost Ball Rule - Rule 27, Johnson, his caddie and everyone in the area began the allotted five-minute search. When the five minutes elapsed, and per the definition of a lost ball, Johnson's ball was deemed to be lost, even though it was found in the hazard on the sixth minute.
This leads to the question of whether or not Johnson could take relief under the Water Hazard Rule. In this case the answer is "no." A player is only able to take relief under the Water Hazard Rule when it is "known or virtually certain" that the ball is in the hazard. In Johnson's case it was not known or virtually certain to be in the hazard at the end of the five-minute search when his ball became lost.
This meant that the only rule Johnson could utilize is the Lost Ball Rule, which calls for the stroke and distance penalty. After going back to the tee and hitting his third shot, he eventually finished with a double-bogey 6.