s.106 isn't as much of bullet proof of a shield you may think, because the next charge shows what happens if you lie if directly asked.
So if the CFO/Police asks what you did to your non-restricted firearm, if you destroyed honestly tell the truth but don't lie. But you are correct you don't need to report destruction of an NR.False statements
107 (1) Every person commits an offence who knowingly makes, before a peace officer, firearms officer or chief firearms officer, a false report or statement concerning the loss, theft or destruction of a prohibited firearm, a restricted firearm, a non-restricted firearm, a prohibited weapon, a restricted weapon, a prohibited device, any prohibited ammunition, an authorization, a licence or a registration certificate.