I work with banks on, um issues, without disclosing too much. Occasionally we find issues with their software workflows, and this isn't related directly to monetary stuff. We're not allowed to have the end result change in any way most of the time. "But we're getting a wrong answer", or "This is costing XX person hours per day" isn't up for consideration. Nothing must change.
Ugh, and on the subject of banks computer operations. Every single department is in deep blame avoidance mode. It's not "find and identify problems" mode, it's "It wasn't me" mode. We had our application performance drop to almost zero (like we dropped to disk operations per minute IOPM) I spent hours telling the customer, this is your infrastructure. So we got infrastructure teams on the call trying to figure out where it was. Not a single one of them were helpful "Everything fine, it's not us" was the first thing out of their mouths and the second was "We didn't change anything".
It took 10 hours of sitting on a call over 2 days to get the NAS team to admit they turned on anti-virus on the NAS side and that the machines were in meltdown mode because the CPU was off the charts. The preceding people didn't even look at the metrics before coming back with a "it's not my problem, everything is fine" response.