Actually its to NOT be considered a firearm:
[...] the following weapons are deemed not to be firearms:
( d) any other barrelled weapon, where it is proved that the weapon is not designed or adapted to discharge
(i) a shot, bullet or other projectile at a muzzle velocity exceeding 152.4 m per second or at a muzzle energy exceeding 5.7 Joules, or
(ii) a shot, bullet or other projectile that is designed or adapted to attain a velocity exceeding 152.4 m per second or an energy exceeding 5.7 Joules.
(Mv < 152.5m/s || Me < 5.7j) != firearm
Therefor his statement was correct, it has to exceed both to be a firearm.