Just because cheques were in the cheque book did not mean that the money was in the bank to pay for the amount and so on.
I remember having to help a not-very-bright catering SAC who was having money problems. The bank were very good with him but he was smart enough (low cunning?) to keep hidden a spare cheque book when I took control of his main one. He never did get the concept of "money in the bank". He had cheques so he could spend them. It did not end well - admin discharge.