The flights were in there. There was a bug in the javascript that creates the dropdown. I'd bet a lot of money that the thing worked fine throughout testing, and then someone made a "small change" at the last minute that broke it.CLT and PHL flights being in the schedule would be a big thing to look for! Unfortunately they often werent there.
The fact that someone could make a change like that is a major process failure, but it happens more often than you'd guess. Especially in web developmment. That's why the term "software engineer" always makes me laugh. If engineers built airplanes the way developers build software, none of us would ever fly.
As far as the US website goes, of course there was some testing. It clearly wasn't good testing, though. Good software testing is hard. So is good project management. In general, in-house IT departments aren't good at either one.