If you are at a Skirmish Site and if the Retailer is under the impression you are involved with the Skirmish (a third party in a permitted activity) then they can safely sell a RIF to you.
As it it would be the Retailer who would be at risk of committing an offense the decision is 100% theirs to make.
This information is provided "as is" based on a non-professional interpretation of the Law and personal experience.