QA is important, but determining how many spaces a line of code is indented is not QA. That is a code review, which is important, but not critical. There should be automated acceptance tests, so that new releases can be shipped immediately. (It's also worth noting that stuff like indenting, naming conventions, etc. can be automatically checked at checkin time. See Perl::Critic, for example.)
If there is some feature or corner case that the users test but isn't in the acceptance test suite... well... yeah, the software is going to be unreliable. So don't do that. Write a test.
(I worked somewhere with a QA department once. They didn't like it when the programmers wrote tests, because they felt their job would be threatened. It was true, so we were asked to only write unit tests; no "integration" or "acceptance" tests. I quit a few weeks later.)