Under Part 4, Rule 4.6K: Interpretation No. 9

In most cases, if a foreign object (such as a ball from an adjacent court) enters the court, the referee should immediately stop play and call a hinder because of the distraction and for safety reasons. However, it might happen that a player would lose a shoe, headband or even a glove. In these cases, the referee should allow the opposing player one opportunity to hit a rally-ending shot if all of the following conditions are met:

1) The referee believes the opposing player is in no danger of stepping on the lost object;

2) The opposing player does not appear to be distracted by the lost object;

3) And the opposing player apparently has an opportunity to hit an offensive, rally-ending shot.

If the player is allowed the one offensive shot, one of the following calls should be made immediately afterward: If the player skips the ball in, that player loses the rally. If the player hits a kill shot or pass shot that cannot be retrieved, that player should be awarded the rally. If the player who lost the equipment is able to retrieve the shot, a hinder should be called.