CR has a strict "we only review code you've written or maintain" policy, which is perfectly reasonable, but how should we treat reviews that rely on 3rd party code (i.e. libraries that aren't part of the standard library)?
The motivation behind this question is a JS/CSS review that included a minified version of a well known JS polyfill for browsers that don't support media queries (Respond.js) as part of the review. I didn't even notice it when I initially reviewed it, but a later reviewer reviewed that portion of the code as well. It's since been cleaned up and had the offending code and its references removed.
How should we handle this in the future? My gut tells me that we should be editing this out and replacing it with a link to the library in question.