"A patent attorney has no duty to investigate the circumstances of the patent application when he does not have notice of the likely existence of material information. That is, the attorney must know of specific information, the materiality of which may be ascertained with reasonable inquiry, before he has a duty to inquire. . . . Mere doubt in the attorney’s mind raised by the circumstances does not appear to be sufficient; rather, the counsel must know of specific information that must be disclosed."
DESA IP, LLC v. EML Technologies LLC, 3-04-cv-00160 (TNMD November 6, 2008, Memorandum)