^ The 'point of putting them in there' is to ensure that entitled groups (those with the 'specific defences') are not prosecuted, but not being prosecuted for something is not the same as not having committed an offence.
What jcheeseright is suggesting is also my interpretation of the law. The VCRA clearly defines importation of a RIF as an offence. Therefore it is illegal. It then goes on to note that those groups who have a specific defence against prosecution will not be prosecuted for this offence if they can demonstrate such as defence (such as the much touted 'airsoft defence' which is not one of those defences found in the original VCRA anyway but was later added here: http://www.opsi.gov.uk/si/si2007/20072606.htm).
The fact that you will not be prosecuted for an act does not mean that act wasn't an offence, and therefore against the law. It may render it 'de facto legal,' in as much as you can seemingly do something illegal whilst knowing you won't be prosecuted for it, but that doesn't actually make the act any less of an offence.
The term you used yourself, "answered for," highlights this; you can't answer a question if the question hasn't first been asked, and you can't answer for an offence with a defence against prosecution unless you have first committed an offence.