Depends on the company, and particularly who manages the team. A good QA manager will fight for their team and make sure a proper analysis is done of the project. Sometimes it's absolutely our fault, sometimes we were given half of the time we said we needed to test and sometimes there are things in the backend that just break on the production servers. If our servers aren't exactly like production, and I've never worked at a company where they are, we can't really help that.