I don't know for certain whether or not they accounted for it, but I'm inclined to believe that your suggestion isn't the contributing factor to the reduced calories. I've read about this effect before, except with reheated pasta instead of rice (both seem rather similar to me) and the pasta was due to the resistant starches as well. This is the article that I read it in before [0].

[0]:http://www.bbc.com/news/magazine-29629761