Yes, you are not misunderstood, there is no need to clarify/interpret this slogan for us. The OP is saying that some mistakes are irreversible. Say, for example, a buggy privacy feature which -- because of fast and loose implementation -- allows users to see previously very private nude pics of a celebrity which he/she had only sent to their partner.

Even if it took only 30 seconds to find the error and the entire site was unplugged from the web so you could fix the bug, the damage is done, it's permanent and it's devastating. Facebook is crossing the line from failures being trivial to failures being potentially catastrophic. Sad, perhaps, by the standards around here, but some people conduct their lives on Facebook -- encouraged by Facebook to do so, mind you -- and you guys are treating it a little more seriously than a hackathon, from the sounds of it.