Even during the campaign they have stuck to an unwrittencode, freely expressing differences but carefully avoiding any escalation into serious conflict.
By rights Noemi could have challenged but she chose to ride by the unwrittencode that dictates that in such circumstances the lead right must give her teammate a chance for the gold.
The Japanese believed in the unwritten Samurai code of conduct, known as Bushido, which held that the true warrior was willing to die for the Emperor and would never surrender.