Have we forgotten Basics of Accounting as a Control Mechanism

Looking at what happened at PNB, we understand the importance of Accounting Entries for any kind of financial transaction or maintaining an audit trail in a commercial organisation. In an urge to introduce new processes (in the name of customer service), many organisations have introduced Single Window Service (may be with certain limits) compromising on maker-checker concept or third eye concept. 

Is there any analysis of 'Transaction Volumes and Velocity' in Banks for each type of branch. Say a Semi urban branch doing a single transaction of Rs.5 Crores on behalf of a customer, should through a real time pop up either for the controllers or an Independent Audit Section as an alert so that immediate monitoring is done and action taken as a measure of control mechanism. Though Audits are conducted at Bank Branches at regular intervals, this is only a post-mortem and the damage is already happened. 

And about SWIFT, how come all the maker-verifier-authoriser process, in PNB, did not look into the details of approvals and was transmitted for such huge amounts. I read in 'The Hindu Business Line' of 15.02.2018, 

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'Multiple fraudulent "Letters of Credit" and "unauthorised messages" were issued from PNB's Brady House Branch for "benefit of a few select account holder with their apparent connivance"

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I do not understand how "unauthorised messages" can be transmitted through SWIFT mechanism. All messages are system authenticated except may be free format messages. If, free format messages are sent, how the receiving bank acted upon such messages is another mystery.

I have scribbled few thoughts and let's see what comes out of further investigation.