Holding that defendants received adequate notice in a False Claims Act case where the complaint alleged a scheme to submit false claims and enough details that the defendants—who "will be in possession of the most relevant records, such as patients’ charts, doctors’ notes, and internal billing records"—could adequately investigate and defend the claims
Holding that denial of leave to amend may be warranted for undue delay, bad faith or dilatory motive on the part of the movant, repeated failure to cure deficiencies, undue prejudice to the opposing party, or futility of a proposed amendment
Holding that to plead a false claim the relator must "state the factual basis for the fraudulent claim with particularity and cannot rely on speculation or conclusional allegations"