I've received quite a bit of training on how to identify improvised explosive devices, and not once did anyone mention "blinking lights." Perhaps you are confusing "training" with "Hollywood conditioning?"
Historically, terrorist bombs are concealed in everyday objects. Trucks were used in the attacks in OKC and NYC. The unabomber sent plain-looking packages. Iraqi insurgents use boxes, concrete, and dead animals. They typically aren't flat PCB boards with lights on them; they have to have some kind of mass to cause an explosion.
Countenancing the obvious fraud that these items could be mistaken for bombs just confuses the public and compounds an error. The boy who cried wolf shouldn't be in charge of the sheepdogs.
It's nice seeing some sense injected, by someone with professional training, among all the knee jerk "hang the Turner people from the yardarm!" stuff. Thanks.
OK, I'll cop to that. Hollywood conditioning it is. Nevertheless, these devices were designed to play into what the public is looking for in a bomb. That is what makes them an effective advertising device.
If you pull such stunts, the state is going to be very, very angry with you. As well they should be.