A person can nonverbally express their desires, and a person can correctly pick up on that expression and act upon it, but they can also incorrectly interpret the signals they're getting. [..] You need to ask.

Am I correctly inferring here that you believe, by contrast, that desires expressed in language, in response to a question asked in language, cannot be incorrectly interpreted? Or at least that such mistakes don't happen "a lot more often than you'd think"?

If so, I'd say this is simply false.