I have also seen alot of high pr sites with tons of backlinks from ahref and majestic(both in history and fresh index), went through them manually and checked all strong backlinks with pr but site explorer shows DA 26 and PA 1 ... and have few records of its backlinks.
I mean from time to time, we have to keep updated to the latest tools.. seo spyglass and ose is way behind right now. OSE doesn't even support how many c-class subnets backlinks one domain has. It goes on with their believe of tweet link.. facebook share link..
I mean how can you trust ose.. when it doesn't even find backlink to the PR5 site which I showed as example.. it can't find then, didn't record them.. so they justify as low PA and DA. That's unfair. I don't really know how this DA and PA thing work, base on what metrics are they giving the points. Majestic gives out ACrank base on how many high ACrank it has to the site, base on their own metrics.. so I don't know about Moz metric and how highly it should be look upon.
Anyway we still need to come up with a strong guideline for blogrolls :S that's the main point!