Where did the CBP thing come from? Sounds like a Christopher Elliot article. That said...

The officer stated without any doubt that the kiosk software was error-free.


This guy needs to be slapped. I'm a software developer. While I try my absolute best to make my programs as stable and reliable as possible, it is impossible to have software with any remote amount of complexity be error free. The CBP software goes well beyond that threshold. If nothing else, a database connection can be interrupted for example, or the database itself could be down even for a moment. Pretending that this is what happened (there are a hundred different possibilities, but the same idea holds in many cases) no normal programmer would have the system infinitely attempt to connect to the database until it works. That's just bad practice. Instead, you tell the computer to try to connect and retrieve the data, but build in a "Plan B" in case that didn't work. It would not be unreasonable for the plan B to go back to the beginning of the program and start from there.