Alpha particles cannot be detected by the (actually existing) app Watson is using, only Beta radiation. Alpha particles get stopped by 5 centimeters of air, let alone the piece of tape Watson used to cover the camera of her phone.
The scientist claims the LIPC prototype ("Sparky") was way too big to fit into an air plane fuselage. However, it fits just fine in his Sprinter van. Even fighter jets are much bigger than that. The device shown is no "bigger" than a regular fighter auto-cannon, especially if yo count its ammunition storage and feed systems.
Those dutchies speak German. They're close, but not the same.
The fact with the door is true by the way.
The Dutch depicted do not speak Dutch.
They are speaking Nordbairisch, a German dialect spoken mostly in Northern and North-Western areas of the Czech Republic.