APG. It is a violation for a defender to attempt a field goal at an opponents basket so if Asik grabbed the ball and intentionally went up for a layup/dunk then the Spurs would get the ball, sideline at FTLE (NBA rule book page 21). However, "A field goal accidentally scored in an opponent’s basket shall be added to the opponent’s score, credited to the opposing player nearest the player whose actions caused the ball to enter the basket" (page 21), which makes this play legal. In the case of an accidental tip all that is required is to make sure the tip happened before the expiration of time (NBA case play 158).