Republican retread or not, a volunteer took a position which sets to make a statement, that the GOP and DEM parties are not the only viable options for voters, and that gentleman has given voters a choice and an opportunity to vote for a Libertarian. Remember that Libertarianism was a major pillar of the GOP big tent for nearly 75 years...
That being said, every Libertarian candidate should be vetted prior to endorsement or funds allocation. The limit of that vetting should be a review of policies to ensure non-violation of the NAP, a signed NAP statement of principles, and a dues paying party member of the state and/or national. Outside of that, candidates should be free to find the winning combination for Libertarians in an election, and should fully be supported by the state and local parties, so long as they are members in good standing.