You can't do due diligence on every single line item to the...

You can't do due diligence on every single line item to the infinite degree - if you insisted on that due diligence would take years. The trade-off to this is to do an appropriate level of due diligence and then put in place comprehensive warranties and protections to the purchaser that allow adjustments and recoupment from vendors if misconduct etc. is detected at a later date into the future, under the warranty period.

EML have stated that these warranties are in place and they are investigating if they have coverage.

It would actually be "really poor form" if EML concluded this acquisition without any warranties or hurt money left in by the vendors.

Bear in mind that these are funds related to dormant accounts which, as the name suggests, are dormant and have not been used for a certain period of time. In due course. funds held in dormant accounts will revert back to EML once they hit 6 years in dormant status. There is probably a very high probability that the vast majority of this cash will come back to EML as those 6 year timeframes expire.