Why do you war someone for respecting your retal policy? It's not a legit reason.
If you warred you'd say, 'yeah, you did exactly what we said and agreed but we arbitrarily decided that it's a cause for war'. That's not legit.

Besides, where's the limit? At 78%? 75%? 70%? Who determines the limit?

What if it happens unintentionally?

Pain, you are a douchbag if you do take another retal if you got 79% already? Again, where's the limit of douchebaggery? 70%? Then why not just say 70% to begin with?