Told ya.
The NBA's Last 2 Minute Report confirms the out of bounds whistle on Stephon Castle was INCORRECT.
In addition, NBA writer
@TomerAzarly received confirmation from the league that Josh Hart should have been whistled for a foul on the Castle drive.
Down 105-104 with 1:02 remaining, the Spurs were already in the bonus and the correct call would have given Castle a golden opportunity to take the lead with two massive free throws.