Me too agree with Steve, Brent and everyone on this.

But DBA should keep in mind that this is not the place for falling and riseing approach. I do agree that we are not machine and as humanbeing we make mistakes. As a human there is always RISK to make mistake. However justification for "Getting FIRED" depends on the situation and impact as explain by Brent and Steve. But personally I do not like for any small issues or problem rather mistakes people blame DBA for poor performance or other server related issues without considering the limitations of system and applications.