"That means firms will have to collect a lot more information on orders and how they were executed for clients - and that means they are going to need more IT systems and data storage."

Hah! Anyone starting their MiFID prep on the 19th of October is most likely in for a nasty shock. We've been worrying about this for about 2 years now. Old news.

"he added, noting though that, oddly enough, customers tend not to complain as much if your mistake means they make money"

As opposed to how Banks currently deal with the problem? As in "if the mistake is in our favour, pay us NOW or be sued. If the mistake is in your favour you need to prove it to OUR satisfaction and then wait for the second coming before we decide to pay"?