Table A 238.2.1.

The athlete, number 35 in the start list, comes in the arena. Trots and canters around the fences while waiting for the previous rider to finish his round. Now it’s his turn.  The bell is rung, and the countdown begins. However, the rider suddenly stops, raises his hand, and the countdown is stopped.

The athlete then talks to an arena staff, and asks her to give him back a shoe lost by his horse.

Consequently, he leaves the arena. Few seconds later, the chief steward asks the GJ through the radio to give a later start number for this rider as he lost a shoe during his waiting period inside the main arena.

What is the decision of the GJ in this case, and would the decision be any different had it been a Nations Cup or a championship ?