Seems pretty far out of whack, but ERA isn't everything. There's a BIG difference between a 5.20 ERA in Chavez Ravine (as a home park) and Coors Field. ERA's can also be pretty severely influenced by fielders who DON'T get to balls that other fielders do get to. Then there's the instance where an error leads to a huge inning, but none of the runs are earned. Even one or two of those can deflate a pitchers' ERA vis-a-vis pitchers who are comparable.

The point is, ERA's are a fair indicator of a pitcher's value, but certainly aren't perfect. I'd be curious if anyone else out there has some idea how PB assigns pitcher grades.