You should read the international standards of audit which are published by the international accounting / audit standards board in short you need to demonstrate adequate evidence that the transaction existed, was recorded in the correct period, that transactions have not been omitted etc. auditors currently use sampling. E.g. you justify a sample size and extrapolate the results for the whole population to give you a confidence interval. DLT will allow them to test 100% of txs. This adds a lot of value.