Is Pelosi accusing Rove of perjury? That can be the only conclusion if the investigation did not reveal Rove's involvement until Miller went to jail. Pelosi is saying that Rove did not testify truthfully when he was before the grand jury.
How would Pelosi know he committed perjury? Grand jury proceedings are supposed to be secret? Did somebody leak it to her? Haul her ass in and force her to reveal her source!