too many quarters in one night

[zanzibar]

After the 3rd quarter A6 tried to sub in for A5 before the 4th quarter started but he reported after the 15 second warning buzzer. The officials wouldn't let him enter the game of course. Then team A explained to the refs that A5 must exit the game because he has already played his 5 quarters that are allowed in one night. The refs decided that they can't overlook this infraction and required A5 to start the 4th quarter. The refs surely knew that at another date that this game would be declared a forfeit. Was the right decision made or should the refs overlooked this minor infraction so that A5 would not have gone over the quarter limit and cause a forfeit?