3. where the judicial authorities of the executing Member State have decided either not to prosecute for the offence on which the European arrest warrant is based or to halt proceedings

This is about dead laws and toleration, like blasphemy or use of light drugs. (I note that the EAW is controversial for over-use in drug cases, including light drugs.) No European judicial authorities have decided that the crime of joining a terrorist organisation shall be non-punishable.

_{*Lunatic*, n.
One whose delusions are out of fashion.}