It's one thing to say that Northwest is managing through the strike impressively well. It's quite another to say they'll be able to get the concessions and other changes they need by mid-October.
It's very much a gut feel, subject to change on a daily or hourly basis.
It won't take much of a switch to change the result, ... There's also the precedent of the other labor groups approving it, including the mechanics, who were thought to be toughest sell. I don't think even those who voted against it are eager to go into bankruptcy.