In the Year 2000 bug example, did Dave do anything wrong?
If Dave was a good programmer he would have questioned the “obvious” oversight and not just programmed his software to only work through 1999. Because he didn't, a software tester should have tested for and found the bug. The team could have then decided whether to fix it.
True or False: It's important what term your company or team calls a problem in its software.
False. It's not important, but the term used often reflects the personality of the team and how they approach the finding, reporting, and fixing of the problems.
What's wrong with just testing that a program works as expected?
At most, that's only half the testing ...