`` that is more familiarity than nearly any other person can claim , '' hammond said , `` and in particular with their language-their customs- '' he stammered over it , and laurence listened with skepticism : what he had learned over the course of those months of captivity , most of it spent in a prison-cave , he had conveyed in his reports , and he found it difficult to believe that his small experience of the tswana should have rendered him an acceptable ambassador in the eyes of their lordships .