The following sentences are from a reading passage. I'm confused on the third sentence - the previous two are just given for context.
日本ではどこに行っても、「きまりですから」という言葉を耳にする。 これを言われてしまうと、こちらにはもう反論の余地はない。 どんなに常識的で正当な理由もこの言葉にはかなわない。
I get that the meaning is something like "No matter what kind of commonplace or appropriate reasons you give, there's nothing you can do about those words." But there's no verb ("give" in the case of "give a reason"), and it would seem どんなに would only apply if there was some kind of verb (for example, どんなに...理由を挙げても). As it stands, shouldn't it be どんな...理由(で)も? What am I missing here?
Thanks in advance.