If Florida State loses in two weeks at Louisville (which I think is very possible) and the Irish win out (which would include a win over Louisville) and a playoff spot came down to one of those teams, who would you give it to? And before you say Florida State, you may want to review the 1993 season and how that unfolded. Who you lose to many times means a lot more in a tiebreaker than head-to-head, especially if that head-to-head game is nailbitingly close and is decided by one play like the FSU-ND game in '93 and yesterday.
Of course this is all hypothetical. The Irish still have two tough road games left on their schedule, but if they were to win out, even their SOS would be better than that of FSU's. I personally think ND would get the nod.