Ford v. Harris County Medical Society

upholding a “same jury” claim when the subsequent indictment charged the substantive crimes under investigation but expressly distinguishing the situation when the subsequent indictment charges false swearing | rejecting a per se rule that would have held use/derivative use immunity inadequate under Fifth Amendment where grand jury witness was also a defendant awaiting trial | government may not use same grand jury that heard witness’ immunized testimony to indict witness for participation in the matters being studied by the grand jury | “the fact that the defendants’ prior art references lead away from [the patent in suit], and that even unusually skilled artisans in the field corroborated the negative teachings, is both relevant and persuasive as to the question of non-obviousness”