Against who?
I don't remember one game where Miami's defense just looked outmatched. Usually it was bad TO's that lead to quick swings. I was trying to find some data to support it and I think the link below does some justice. In '09, the defense wasn't great. It was Lovett's first season at Miami as DC. In his second season, the defense was on par with our 2017 defense in terms of yards/play and overall.
I'm not saying that the defense was National Championship level but the ACC was still up for grabs. If we would have stopped throwing picks, those four years would've been significantly better. I don't think Randy/Lovett's defense was the issue.