Clemson finished that game with a 42% post game win expectancy, their only game under 50%, with a 72% offensive percentile performance and 25% defensive performance. Clemson finished with a 36% success rate on offense, which is poor, while giving up a 42% success rate defensively, which is about average.
A&M is the only team Clemson played (excluding Florida State, which is a dumpster fire) that was within 10 spots of them on the team talent rankings on 247, with Clemson at 6th and A&M at 16th (incidentally Notre Dame is 10th). In essence, Clemson played one team that was within their range talent wise that had a good to very good staff, and that game came down to the final seconds.
This isn't to say Clemson is overrated, they are not. A lot has changed for them since that week 2 game, and they have certainly gotten better and more efficient, especially on offense. But, they've also done that against teams that couldn't come close to matching their roster talent, and Notre Dame can come closer than anyone has this season. They also have an excellent staff, and Clark Lea can certainly give Mike Elko a call to pick his brain on how to slow Clemson down. Anyway, I think Clemson should be favored, but these double digit spreads are over the top to me. The teams aren't as mismatched as we're being led to believe.