If he can come and earn a scholarship why not just offer him? I feel he is a good enough athlete that he would see time immediately in special teams. For those that don't think that warrants a scholarship, go back and look at how we fall short every year in our 85. BK, again IMO, has a plan to offer scholly to walk on's which I think is great. However, I think Justin can be, not only an added improvement to this team in small manners, but he can be worth the scholly than some walk on that may benefit from us not offering his "type".
Also, so what if Purdue make him a center piece. If he is a big target for Purdue, I would think he could benefit ND in some fashion. As far as being Drue's brother... Again, Drue was said to be a "no body" when he was recruited. He changed that in week 1. Gene's do matter and Justin has shown to be pretty solid from the athlete standpoint.
NOTE: I fully respect the walk on that earn schollys. Do not want to take anything from them. We all know that they will be the first to lose an opportunity if we can just offer a player off the bat.