Auditors

"“Interrogation” is of course exactly the wrong word and if I’m dealing with a firm that has handled this sort of situation before, one that is utterly forbidden."

Indeed, it's "Root Cause Analysis" but in this particular instance I suspect that PWC or similar will be in to do audit of how the change controls allowed this sort of c0ck up. There are FSA requirements around this sort of control, but more chilling for RBS is the fact that they're also an NYSE listed company and are subject to the rigours of Sarbanes-Oxley compliance, which makes for an even duller and intense process.