1) The SEC benefited, SOS-wise at least, for the entire season and in the committee "deliberations" (LOL), from an egregious officiating failure by SEC officials in the ND-TA&M game and, it appears, nobody even raised the issue in the rankings.
2) The ACC's only playoff-worthy team did not receive the automatic bid as conference champion because of the ACC's own stupidity in not having a rankings-related tiebreaker for its CCG. The ACC wasn't made to pay for that error, ND was.
Because of these mistakes of others, an ND-team capable of winning the championship was excluded from that opportunity. That is not just.