My input: Never assume anything.

1. you don't assume QA will always do their job
2. you don't assume Dev will always do their design review, code review, unit testing, and some level integration testing
3. you don't assume your manager is always on your side
4. you don't assume others are coming out to get you, personally.

That's why no matter how good or experienced you are, process is important, and document is important. In plain English, cover your own a$$, because everyone is doing that.

In some small shops, proper design/code review is not possible, and lengthy testing cycle cannot be afforded, but one thing you always need to do, that is - no matter what pressure you are getting, a written sign off email from QA group, before ANY production change, is an absolute must.

Dev make and break codes, QA find and miss bugs, and Users request and blame systems, those are normal life experiences in software world. It's no big deal, and you can't make it personal, nor should you assume others are making it personal.

Mistakes happen, as long as you are following important procedures, you are fine, other teams can't attack you, and your boss will defend you even if that does happen. Therefore, it's very important for you to keep your boss in the loop of all the happenings.

One more thing, you need to maintain the expectation of end users, don't give out promise/estimation easily. Put yourself and your team above customers:) It sounds wrong, but it benefits you:)

Just my 2 cents.