> <a class="button" href="#"
> onclick="_gaq.push(['_trackEvent', 'Download',
> 'BAG004',
> <http://psdcovers.s3.amazonaws.com/wp-content/upload>
> s/2013/07/PSDCovers-BAG004.atn_.zip']);"

Looks difficule for me for the basic httrack javascript parser - did you allow
all external ZIP files by the way to be sure ?
Scan rules / add :
+*.zip