Had a bit of trawl through the various articles posted in the innerweb about this alleged incident, trying to find the source. Didn't succeede in that, but did notice that all of the articles seem to be based on rumours spawned on enthusiasts internet forums.
As the story is picked up by other media, something very interesting happens that turns rumours into facts. One article quotes as follows: "A netizen going by the name "Boeing" who claimed to have heard the recording ...". In subsequent articles, who are clearly doing little more than a cut and paste job, the same information is presented as facts, and without naming the source. In essence it comes "recordings clearly shows".
So what we have here seems to be a story spawned on an internet forum for enthusiasts, picked up by another site that's monitored by "the media" and eventually published.
I'm not saying it didn't happen, only that the sources of information so far are of unknown, and questionable, quality. And that we're essentially sat on an internet forum, discussing rumours that seem to have its origins on another one.
Still, better than watching TV I suppose.