Doing an HPLC test is really not that difficult. If you do it correctly, you should get a correct result.
Or maybe it's just marketing that decides how long to wait to do a test.
"One method determines total amount of heat units in 7 minutes, while the other provides total amount of heat units as well as separation of all present major and minor capsaicinoids in 20 minutes. These improved techniques provide inexpensive and rapid methods for quantitative and qualitative analysis of capsaicinoids in Capsicum fruit samples along with good sensitivity and no interference or confounding peaks."
"The most accurate method for measuring heat in chile peppers is high-performance liquid chromatography (HPLC). In this procedure, fruit are dried and then ground. Next, the chemicals responsible for heat are extracted, and the extract is injected into the HPLC for analysis. This method is more costly than the Scoville test, but it gives an objective heat analysis. Not only does this method measure the total heat present, it also allows the amounts of the individual capsaicinoids to be determined. In addition, many samples may be analyzed within a short period. The NMSU Chile Breeding and Genetics Program has analyzed more than 5,000 samples using this method and has found it to be reliable and consistent.
As the demand for chile peppers increases, the heat level of the crop is more important, and an accurate and precise measurement of heat is necessary. Several testing laboratories perform the organoleptic and/or HPLC methods. The American Spice Trade Association (ASTA) publishes the procedure accepted by the spice industry. Several laboratories that perform such tests are listed below."
Here...
And More... Here the Bhut comes in at 329,100.
From what I can tell the standards for analysis are determined by the American Spice Trade Association. And why should the record heat value be some kind of average for all pods around the world? It should just be the hottest pepper. No matter how much you stress a Tabasco, it's not going to have the heat level of a Bhut.
Perhaps this testing is more relevant to the use of the pure capsaicin for medical/military use?