I'm the one who declined that flag. While the link in question does point to some offensive language, we really don't have any control over what does or does not get posted on a third-party site, nor are site moderators really in any position to judge people based on what they decide to post elsewhere. The very fact that his post here was written in a polite and respectful manner (despite the obvious bias demonstrated in the linked profile itself) is actually a point in his favor.
The best I could do would be to delete that comment, including the associated link. But given that it was posted in direct response to someone explicitly asking for the audio (which I considered rather important for answering this question), that would just leave the request for audio hanging, which really wouldn't help the questioner get his answers.
Ideally, an alternate link without the naughty words could be provided with the same audio, which could replace that link (and, optimally, end up folded into the question proper). However, as best I can tell nobody has even asked for one, or even informed the OP that his link was inappropriate. That does not require moderator intervention; anyone with commenting privileges could do that.