How to fix a rule that is being abused based on defective wording?

Background: an organization attempted to regulate parking in a visitor's lot, the objective being to reserve certain spots for visitors only. Residents would be able to use the lot only if they owned a third vehicle, given that their garages can hold only two cars. To prevent their parking a junker in the visitors lot the phrase "... it must be registered and in running condition" was included.

A resident now seizes on a loophole to put an unregistered junker in his garage, claiming that the third car that is now (cynically but theoretically legally) parked in the visitors lot IS registered and therefore compliant. This is, of course, true, and the organization wishes to amend to rule to state that "all the vehicles in question" must be registered and licensed.

Fixing the wording would obviously affect only the one violator. The violator claims this would be illegal, the same as if a new rule were created specifically directed at him (like a bill of attainder). The organization, on the other hand, claims this would only be a clarification of what was clearly originally intended.

Is there a rule of law that allows an amendment of a rule (CC&R) that only fixes a semantic defect, completely corresponding to what was obviously the original intent, or is the violator entitled to a lifetime exemption based on what is admitted by all to have been an original loophole overlooked by the organization's (incompetent) lawyer?

We welcome all thoughtful comments. Thank you.