Just an idea, implement in the game when the last counters from a Battle is removed, if you click decline, have the game verify with "Are you sure?" Yes/No, just like how it works when you target your own creatures with a damage spell. I can't tell you how many times I've accidentally hit the decline button because you're clicking "Resolve" through the combat step and just hit "Decline" because the card popped up and you're just trying to click through combat.