I have to say that if one third of errors in this paper were committed by editors, something's wrong. I can't dispute this editor's figures; she seems to have researched them pretty thoroughly. But am surprised to see that she thinks her paper's reporters 'fess up quickly.
It has been my experience, at at least two newspapers, that assigning desk editors tend to point the finger at the copy desk all day until those editors come in, do the research and establish that the originating editors or reporters were responsible. It's not clear to me if she's distinguishing between copy and other editors.
I do think that a policy ought to be consistent--either you blame the individual, always, by title, or you never blame anyone. That may seem unfair in any given instance but it does reduce the finger pointing and fights over who did what.
Speaking of errors:
Some Mistakes Are More Entertaining Than Others.
Yes, they are.