what does Paul tell Franz Kemmerich's mother about Franz's death ?

Paul lies to Kemmerich's mother. He tells her that Franz died an instant death on the field and did not feel anything. The truth, of course, is Franz died long and painfully. Death took hold of Franz like a specter, turning him a yellow grey complexion. Paul was charged to look after Franz by Mrs. Kemmerich. I suppose Paul lying in this context saved them both some pain.