Coin a boss when you have forgotten your Mogu Runes

If you have not yet collected your weekly mogu runes of fate and kill a ToT or 5.2 world boss, you can still coin that boss as long as you, within the normal roll timer window, make it to your faction's shrine (hearthstone or portal works) and portal to another continent (confirmed with Wrap of Unity). 

After obtaining the runes and porting to another continent the roll window will pop up on your screen allowing you to coin the boss that you recently killed.