Undetectable e-bikes

I recently came across an ad for a Story Bicycle road bike that is almost indistinguishable from a regular road bike. Replace the handlebars with drops and you would be hard-pressed to know this isn't a regular road bike. It has pedal assist, so you won't see a throttle grip and the battery is concealed in the frame.

Story Electric Road Bike

It comes with a 36V, 7Ah battery in the down tube and a motor in the rear hub capable of generating up to 350W of power. The battery weighs about 2kg and the motor and crank sensors probably weigh another 3kg. So how much help would this be on a 200k brevet? Does the extra weight offset the power assistance?

Let's do the math using data from http://www.ftexploring.com/energy.

Thirty-six volts times 7 amp-hours = 252 Wh = 907,200 Joules of energy in the battery (252 x 3600). It takes 10 Joules to raise 1kg by 1 meter so this battery can raise 1kg by 90,720 meters or it can raise the extra 5kg of the battery, motor, etc by 18,144 meters or nearly 60,000 feet. That's far more climbing than most brevets have so a significant portion of the battery's charge is available to propel the rider forward.

So on a ride with 15,000' of climbing, 25% of the battery is used to raise the battery, etc over the climbs, and 75% of the battery would be available to aid the rider.

So I've established that the energy in an e-bike like this far exceeds the cost of the extra weight. While they may be fun to ride, they're banned from all randonneuring events due to article 2 of the rules below (my emphasis).

Article 2

These brevets are open to any amateur cyclist regardless of his or her cycling affiliations. Any rider under the age of 18 must have consent of his or her parent or legal guardian. Any form of human-powered vehicle is acceptable. The only stipulation is that the vehicle must be powered solely by the rider.

As event organizers, how do we spot riders trying to cheat with bikes like this? The one thing all e-bikes have in common today is the over-sized front or rear hubs. Even though the manufacturers can hide the battery, they still cannot hide the motor in the hubs.