National Review gives a good background into Paul Ryan's debate prep.
During the final debate prep in Florida, Olson hectored Ryan. He pestered him and smirked. A couple of Ryan confidants wondered if Olson was overdoing it.
On debate night, the real Biden was worse than Olson’s caricature. “I thought Ted was absolutely great, but I didn’t think Biden would put on such a show,” a Ryan official says. “Clearly, I was wrong.”
“Looking back, the best thing that happened during that boot camp was Olson getting under Ryan’s skin,” says a Romney strategist familiar with the sessions. “He knew how to frustrate Ryan. That’s harder than you think.”