Last 3 seconds:
Source: Jan Stradling. More Than a Game
THE US PROTEST
The US is protesting the extra three seconds granted because the game, according to FIBA rules, was over.
The US was shooting the second of a two-shot foul. This free throw was made. At the point the free throw was made, there were three seconds remaining.
At this point, according to FIBA rules, neither team can call a timeout. The official score sheet does not show a timeout in the last three seconds.
The opponents played the ball and ran off two seconds. According to FIBA rules, this was the only official way to continue the game.
With one second remaining, spectators ran onto the playing court and referees stopped the game at this time. At this point, with one second remaining, according to FIBA rules, they acted correctly.
When the spectators were removed, the game was started with only one second to go.
The one-second as played and the horn sounded, officially ending the game. The official score was US 5O, Russia 49.
According to FlBA rules the game is officially over.
Comment: That's a good analysis of the situation made by the Americans. There were no reasons to roll clock back. In their protest Americans made only one mistake - they insisted that game have ended after Soviets' second attempt, being unaware of the reason why that attempt have been voided. As it's well known now, the reason was that the game clock was not properly set at that moment, so even if Soviets had scored, it wouldn't be counted.