When testing the Automatic Activation Device (AAD), several errors are made. CSI Stokes uses a pressure bottle to 'raise' the altitude to 2000 feet. Pressure decreases with altitude. He would have had to use a vacuum pump to raise the altitude and this would take several minutes to raise the altitude. The pressure/altitude reading is in absolute pressure. 0 feet would be 1 atmosphere (1000 hPA) or sea level. Las Vegas is already at 2000 feet altitude. The chamber with doesn't have any pressure seals, just a latch. This would prevent the chamber from holding pressure or vacuum. This would keep the chamber from exploding since it is made with Plexiglas panel that are far to thin to hold 2000' of vacuum.
It is stated that the defense contractor used a hyperbaric chamber to simulate high altitude. Hyperbaric chambers are used to create high barometric PRESSURE within them which is the opposite of high altitude. What they would have used to simulate the altitude would have been a hypobaric chamber.