Good question. Even if it does not load, it should still show the adsense code in the html. But looking at some random post, I don't see it:
http://web.archive.org/web/20150304235943/http://www.gwern.n...
Adsense is usually a script loaded from googlesyndication.com which is not in the source here.
Maybe archive.org rewrote the html so much that it is not there anymore?