I'd say that it's not a good path to tread to have courts deciding who can and can't be on the ballot, however, in this particular case, it was put to the voters, and these guys knew the rule when they broke it, so c'est la vie
As for their argument, I'd say go with it... Let them run, let them get elected, then bar them for the term... That's actually how the wording works out... Theyre correct that they can technically run, but it's pretty specific about being unable to seve the term.
Fuck around and let a district go unrepresented for a term because legislators wanna play the "well ackshually" game, and the voters will sort that shit right out.