Who waylays Grey on his way to the American hut, and what does he want in Chapter 12?

As Lt. Grey heads towards the American Hut, a British Colonel named Samson walks up to him and says that he would like to get Grey’s views on the Singapore Campaign for a history he is compiling. Grey says he would be happy to discuss it the next day, but Samson insists on discussing it right then and there. Grey has no choice.