That is incorrect. The crew in question were free to bid the 18-day just like every seniority-list pilot and had ample time to do so. (after all, they knew about this trip a full year in advance having flown it the previous decade....)
This is the type of trip ideally suited to the 18-day schedule. The only caveat, is in order to bid onto the 18-day schedule, the crew would have had to bid off of their respective 7/7 schedules. (if they desired, they would have been free to bid back onto the 7/7 schedule during the next bid period just like every other seniority-list pilot)
The "limitation" this crew sought relief from had nothing to do with the 18-day schedule, but rather they wanted a special exemption made on their behalf to fly the trip without ever leaving the 7/7 schedule. - in other words, they wanted special treatment. (Bubba Club anyone?)
Because there was a remedy to this situation within the boundaries of the CBA (bid the 18-day, fly the trip, then bid back to 7/7 during the next bid period) I believe the union was correct in their decision to deny such an unprecedented "Bubba Club" request.
The union response was provided prior to the close of that particular bid period (again, allowing the crew sufficient time to bid the18-day). For reasons unknown to me, they choose not to.
Bottom line is THE CREW screwed this particular owner when they choose not to bid the 18-day.
Of course, it's much more fun to blame our union.
Jusssss sayin'......