I took that comment to mean that once someone is dead by suicide, or any means, they aren't capable at that point of concealing their corpse. If we go with suicide, it seems that would indicate that he wasn't thinking as clearly as he normally did. Therefore, he might lack the necessary faculties to plan and commit suicide in a manner and location where his body would not be discovered. JMOO
I thought they were joking, but ICBW.