There's no such thing as absolute fact.
In regards to history and other areas of "interpretation" yes, this statement applies very well. What critical thinking offers is also the consideration that there are OTHER VIEWS that must be considered and evaluated whether they are accepted by larger educational organizations or not, especially if they have evidence and an argument to support them. By their very consideration, it facilitates expansion and the advancement of understanding of the field.
This is probably the single most beneficial aspect of critical thinking in regards to the study of history. It is this aspect that I often see lacking in Japanese education, as well as East Asia. Heck, it is needed more in the United States as well.
As I stated above, one of the "sins" in the teaching education of history is that there is a single accepted version of history... the one promoted and enforced by the Japanese Ministry of Education of course. The idea of a "right" version of history I ran into all too often, and when you have two people with two different versions of "correct history" speak without the ability to separate the issue from personal attacks. It's a problem. When you have millions and millions of people in East Asia accepting different national versions of history depending on a country with nationalist fervor and almost no personal study or research on the topic, let alone having been there... you have a REALLY BIG PROBLEM.
This is where critical thinking can bring the biggest benefit in the Japanese education system, international and interpersonal relations between nations. The open evaluation and consideration, not being a rebellious act, but an expected and encouraged path of thinking that is not meant to attack, or assault a country, nationality, but simply to gain an understanding from each angle.
That, above, is the benefits of introducing critical thinking in a stronger form in Japanese education.
I agree with many posters that history is one of the fields that would be most beneficial. My hesitation only comes from the opposition that I know it would certainly face if it was taught to kids and the backlash that would occur harming the movement for critical thinking as a tool of education in Japan. Changes don't happen over night.