here.) The proffer agreement states that self-incriminating statements cannot “be used to determine the appropriate guideline sentence.” But it lists exceptions, including “to rebut any factual position taken by or on [Loesel’s] behalf in connection with sentencing issues or for any other reason.” He asserts the exception does not apply. Not so. At sentencing, he claimed his girlfriend’s pseudoephedrine purchases were not' attributable to him. According to Loesel, his claim is a “legal theory,” not a factual position. Drug quantity is a question of fact. See Walker, 688 F.3d at 420. The government used his proffer statements about meth use and distribution to rebut Loesel’s factual position about drug quantity—which is permitted under the agreement. Cf. Perry, 640 F.3d at 812-13 (<HOLDING>). The district court did not err in using that
holding the proffer agreement was violated where information  from the proffer session could be used against the defendant only if he  materially contradicted statements made during the proffer sessionand  only as impeachment or rebuttal evidence or as the basis for a prosecution for perjury or false statement  holding that the trial courts statement it would deny the defendants request to make a bill at this time did not discharge the appellants duty to proffer the excluded testimony for preservation of error holding that for a section 10b violation the sec must prove that the defendant in connection with the purchase or sale of securities made a materially false statement or omitted a material fact with scienter and that the plaintiffs reliance on the defendants action caused injury to the plaintiff holding that the elements of a claim under  3729a2 are 1 that the defendant made used or caused to be made or used a record or statement to get a claim against the united states paid or approved 2 the record or statement and the claim were false or fraudulent and 3 the defendant knew that the record or statement and the claim were false or fraudulent emphasis added holding that duress evidence was properly excluded where defendant failed to proffer evidence on each element of the defense