There are only several hundreds carriers of the Milano mutant allele. Do you think its frequency can be even near 1%? It's a rethorical question of course.
Insofar as the boundary between a polymorphism and a mutation has been arbitrarily defined as a 1% frequency for the least common allele (according to your citation), vinmantoo’s statement in #msg-75805071 does not strike me as a flat-out misstatement.
The point was that Vin was agreeing with her substantive argument (that the size of the population was so low it wouldn't show up in an epedemiological study) - and then disagreeing with the particular terms she use. She was just rebutting on the semantics issue.