Yeh, the weird thing I am noticing is that the canonical tags are already present on this domain, and it's not picking up ALL of the pages with canonical as duplicates.
I'm not really sure what's going on, but when in doubt, I always Google the following query:
site:domain intext:block of text unique to that page
If there is a duplicate content issue, Google should tell you that by showing more than one result. If it shows only one, then Google is reading your code right.
I know we all love Moz and want them to show we have no errors on our sites, but at the end of the day... don't we really want Google to find no issues with our sites, not Moz?