That's it in a nutshell. Of course, the only people who care about the distinctions you're describing are the designers of the components who want to make clear that the problem isn't in their part of the system. The person who wrote the FP+ code can yell "it's not a bug, we designed it this way" until he's blue in the face (and the one who designed the reservation system doesn't care, he retired 10 years ago) but whoever designed the integrated system cannot.
I would only add that its the MANAGEMENT of the designers who yell it isn't our fault! (and btw, give me my bonus!

I'd have thought this stuff would shake out during the tests since it seems like lots of folks like to tweaks their reservations until about 20 minutes after they arrive
