I have a mixed perspective. On the one hand, imports come with risks and show offerings are basically variants of "speak now or forever hold your peace" situations (for both sides of the transaction) most of the time to me. Imports for adding new blood or new localities, for some kinds of keeping and some kinds of projects, are part of herpetoculture. While I think it might be great if we were already beyond that or if there would be no further need/use, some things are simply not at that stage yet for individual hobbyists and the species/localities involved.
So while I understand the desire to add new blood, the situation was perceived to be at least somewhat iffy upon examining the animal at the show. Also, having been around the block myself, I trust the data delivered by my eyes more than the data delivered by my ears (unless I hear negative respiratory indicators, I guess) when inspecting an animal in person while talking to a vendor. For example, when people tell me an import has been "treated three times" (or whatever), is "a chowhound" (or whatever), and is "heavy as a brick" (or whatever), I just assume that such noise is all crap and proceed as if the animal needs full adjustment and establishment to have a chance of surviving. I can get lucky with trust, but I am more likely to eventually get burned with trust.
That said, if the account as described is how things went down at the show, there would have been some misrepresentation involved in the description regarding the animal's establishment status or testing/treatment history. After being burned once and having had one or two near misses, I quickly learned to limit faith and take extra precautions. Also, the buyer was passed around to various representatives that prolonged concerns of not being dealt with, so I understand the delay leading to dissatisfaction.
All in all, I would have looked at the prospect of buying this animal as a pure risk and would have not believed any health status claims. If looking iffy to me at a show, I would either accept the risk and let come what may or move on without buying because I would not want to add to my bucket of headaches. I understand why the buyer has and is airing his grievance, though, and it might not have come to that if 1) there was no (alleged) misinformation and 2) communication/response from the vendor had been more rapid, complete, and conclusive.