There are questions that people cannot answer.
Questions such as "what time is it?" or "what colour is this chip?" require information external to the question. So all you can say is that the room does not have access to this information. Otherwise you could say that a blind person, or person without a watch cannot understand chinese.
Just as a person is unable to answer all questions. We cannot excpect a program to answer all questions. If I ask someone "What time is it?" And they answer "I don't know I don't have a watch." I cannot assume they don't understand english. If I ask "What color is this chip?" and they reply "I don't know I cannot see the chip." Again I cann assume they don't understand english. Even if they answer a question wrong. "How many feet are in a mile?" and they answer "isn't there 12?" I can't assume they don't understand english, they may just be english majors.