With a 7 point lead, Ohio St converted 3rd & 9 and 3rd & 11 deep in their own territory. Had they not converted either of those, ND would have gotten the ball back with sufficient time to get a touchdown, and (as Weis later divulged) a game deciding 2-point conversion.
Yes I realize there was a large difference in total yards in Ohio St's favor but that doesn't make it a blowout. Nobody's saying we blew out South Florida in 2011.