In Bag End, Gandalf and Frodo are talking about extremely sensitive topics with the window wide open. Anyone could have listened in to their conversation and ran off to gossip about it all over Hobbiton. And, indeed, somebody did eavesdrop! Sam. They were just lucky he happens to be so loyal and non-evil.

Then, not much long afterwards, Frodo appears to have learned nothing. In the Prancing Pony inn, they again (albeit without Gandalf present) sit and discuss extremely sensitive matters, repeatedly referring to Frodo with his real last name, with the window wide open in the parlour.

Strider should have known better. But only after they have already laid out all the information does he shut the window. One of the Black Riders could easily have been lurking outside, even if they don't attack physically in the daytime.

Both Gandalf and Strider (Aragorn) are shown to be extremely intelligent, wise, resourceful and careful in general, except for these two instances. Of course, "the story dictates that it has to happen" with Sam so that he has an excuse to go with Frodo, but in the second example I've just given, there seems to be no reason that they had to sit with the window open in there. In fact, I assumed that it was locked tight until the moment that the book describes to me that Strider finally shut it.

Would I ever bother to ask a question like this for a poorly written book? Hardly. It is only because of the attention to detail and ultra-high quality overall of this work that I do so. I feel as if there's probably an explanation which I haven't thought of.