In Chapter 11 of All Quiet on the Western Front, the orderly's being mystified has nothing to do with the fact that Kat is dead. The narrative reads, "The orderly is mystified. 'You are not related, are you?'" Paul has agreed to take Kat's paybook and his personal effects. It is obvious that Paul is distraught over Kat's death--he has just spent the last few moments in denial over Kat's death. Paul was incredibly close to Kat during the time they spent in the war, and Paul regards Kat as a brother. Paul treats Kat as if he were family, and the orderly is mystified by the close relationship that is revealed by Paul's reaction to Kat's death. The orderly sees people die regularly--similarly, Paul has seen men die regularly. However, Kat's death is not an everyday event--for Paul, the death of Kat is the end of his hope.