Ok, let me see if we have this right. There might be a hoax. There might be a hoax that goes on for 5 years. There might be a hoax that uses Nightwing's own mixtape to fool him.
Gee, I guess there's no point in ever even talking about BF because there
might be a hoax involved in every case. So....
I guess there's nothing to talk about here anymore. Ok Paul, I guess its time to put that
closed sign up in the window.
[Yes, another wonderful example of my under appreciated sarcastic wit!] 
The point is not whether there
might be a hoax, there might always be a hoax. The point is whether or not the recordings seem to indicate otherwise. Because if they don't at best they are interesting, particularly if one can come up with good reasons they might not be. And if this field, usually, that's the best you can do. I have no intention, however convincing they might sound, of putting them on a shelf in a jar labeled "certified BF calls".
If the only point you have is that there
might be a hoax... so lets
assume there is a hoax, so lets
not look too closely at the actual recordings, then we can conclude that they
are a hoax, and then later use them as examples of a long-term hoax... then I think you're preaching to the wrong choir. Try the CSICOP board, they ought to be an easy sell.
The recordings are data, which might (with effort) become evidence, they will never be proof from them. I would be more inclined to take the current skeptical position seriously if they leaned forward in their armchairs, tapped at their keyboards for awhile, and using readily available primate calls (of whatever sounds they think are appropriate) fashioned something that sounds substantially like the recordings. Then, if the listeners agree that's what you seem to have done, you will have gone a long way towards convincing all of us that there is no reason to think the calls are interesting. Just be sure to fastidiously document what you did and how you did it so it can be replicated during peer review. Then you would have the SI part of the above acronym. Nightwing's mixtape is not needed unless the calls on it are "super special calls" unavailable from some other source.
Now, if Drew had kept quiet, and waited, until some howling beast had crept up and started screeching, to take his gurkha knife out and use it we
might have had another DNA sample. There may have been collateral damage. You could say, "One less Skeptic, one giant leap for mankind." They would even name schools after him, for heroically dying to prove BF exists. That's the way I would prefer to go. Then we would have something really interesting to debate!
Just kidding, I'm sure he would make it out with just a flesh wound... and the hominoid blood stained gurkha knife!
But in seriousness, it would have made more sense to wait until the "hoaxing" commenced at which point attempting to surprise the hoaxers in the act would have been the more logical thing to do from a Skeptical perspective. Observing, or better yet, photographing/videoing hoaxers in the act, would have been the most effective way to turn the tables. A publicly announced prior warning would have kept them from making an appearance, or guaranteed it would be at a considerable distance. The only apparent reason for doing it is to make it less likely that an attempted hoax will take place at that time. Since I assume that the BF calls were not a guaranteed, money-back phenomena their non-appearance would prove little. Perhaps the intention really was to collect a cryptic DNA sample, and this warning was meant to spare the lives of any hoaxers who were present. Hmmmm.... poor skeptical tactics, not bad for Kamikazee Cryptozoology. Maybe they would have named schools after him...?
But at this point there doesn't seem to be evidence that there was a hoax. No one has been observed hoaxing the calls, to our knowledge. No one seems to have produced a study of the recordings themselves indicating that there is anything wrong with them. Arguing points without any evidentiary basis to believe in them is supposed to be what slack-brained Believers are said to be specialists at. If the shoe were on the other foot I'm sure this would be being pointed out.
In terms of hoaxes there are three end results: the hoaxers reveal themselves by accident or through the efforts of others, the hoaxers reveal themselves to demonstrate their own superiority and to gain notoriety, or the hoax goes unrevealed indefinitely. The final form is exceedingly rare, particularly when monetary reward or criminal prosecution is not involved. As to the typical duration of a modern, highly successful hoax, I have two words for you:
Balloon Boy.
PR
