My point is that if a bank refuses a loan on the basis that someone gamnbles, BUT DOESN'T TELL THE CUSTOMER the reason then the customer cannot supply relevant extra information, such as that the transactions may have been made on behalf of another person.
So it's a sceret rule, and secret rules disadvantage the consumer, as the consumer cannot be expected to know anything about rules deliberately kept secret.
Note also that credits for winnings were completely disregarded, only the amount of debits were assessed, gambling winnings are not seen as an acceptable source of income!!