And the guy who found it is also a well known variety specialist so he should definitely know the variety if he saw it.
Everyone looks for the 1998 - 2000
WAM's, but they COULD have occurred on any year(s) from 1994 - 2008 from Philadelphia and from 1994 - 96 at Denver. Sure none have been reported except the 98 - 00 and possibly the 96, but if they ARE out there and no one looks for them they aren't going to be found or at least won't be found for a longer time. New varieties are rarely found by people looking for known varieties.