... And he doesn't even know about this site!
He is the lead user for an upgraded version of their card payments system.
A staff member phoned earlier with a problem that they didn't understand. BF looked into it and found that they had taken a payment and not noticed that the payment they took prior to this one was not submitted, and that it had attached itself to the most recent one meaning they took more money from the second customer than they should have. It was entirely staff member's fault and responsibility.
The staff member asked him if he could call the customer and explain to them what had happened. His reply was, "and why would I be doing that?"
I felt quite proud of him because he can get quite short with people at work and I thought his reply was very diplomatic!