You do not need to apologize, it’s my fault – my English is very bad. I will try to speak more clearly: the shield bonus continues to operate even when the enemy flees from the battlefield.
Perhaps the bonus should be reduced, but unless the character drops the shield, I suppose that it is still possible for the shield to block some kind of attack, whether it is intentional to block it or not.
"It is not death that a man should fear, but he should fear never beginning to live." ~Marcus Aurelius
Game: "Characters with a height advantage against their opponents are harder to hit"
Me: "That's not true, and my short axeman is living proof!"