I've heard it when Charlie's "Jersey" routine rubs a recruit the wrong way, and I have yet to hear anything to the affect with Montana.
Honestly, I think it boils down to:
a) Not wanting to compete at the same position as his brother (as in make his brother feel bad once he blows by him on the depth chart).
b) Not wanting to follow in Dad's footsteps.
c) Not having that much interest in the Irish (even back in last fall, I remember hearing that he was fairly fond of USC).
d) Our staff not being that high on him. Weis favors tall guys, and pocket passers more often than not, and he doesn't really fit that bill.
For someone who wasn't very interested in the first place, in spite of a boatload of info on ND at his fingertips (two siblings going there, probably countless family trips to the campus, I'm certain Dad could tell him anything he wants to know, etc), the staff probably came together and said it wasn't worth the chase in the end. Other guys had more interest, and projected as either an equal or better fit for the scheme the Irish run.
Its more compelling to think that there's a conspiracy behind it, but I really think its the little things adding up, hard as that is to accept for many, including a pocket of nostalgic Irish fans that are beside themselves.
EDIT:
As for the Golic brothers, Mike is a project but he is legitimate. His early offer was a combo of wanting momentum, having a need at Oline, and planning on taking two centers so being able to take on a weight room project.
As for Jake? That was pretty much political. With the brother already on scholarship, and Jake getting D1 interest, we pretty much had to follow the precedent we laid with Mike.