In this case there is much confusion as to what an ebike is.
An 'electrically assisted pedal cycle’, or EAPC, is a bicycle with an electric motor that meets the DVLA's EAPC rules. The key ones to obey are:
• Over 14 years of age
• A maximum power output of 250W
• The pedals must be in motion for electric assistance to be provided*
• No electric assistance over 15.5mph (25km/h)
*post 2015 may have a 'twist and go' throttle that assists the rider without pedalling to a maximum of 3.7mph (6km/h).
The boys were travelling at around 30mph and their legs were seen to be not moving (not pedalling) therefore exclusively powered by a twist-grip throttle. This indicates the ebike was not an EAPC.
Any electric bike that does not meet the EAPC rules is classed as a motorcycle (L3e) or moped (L1e) and needs to be registered and taxed. Riders need a driving licence and must wear a crash helmet.