May evidence be so unduly prejudicial to 'one juror' in a capital sentencing proceeding that it renders it fundamentally unfair, particularly in jurisdictions requiring juror unanimity?

(Capital Case) Mica Martinez is a Native American steeped in Comanche culture. Mr. Martinez’s defense counsel at trial warned the prosecution of putting on a “wild card” ex -girlfriend, fearing she would try to harpoon Mr. Martinez’s case. The prosecutor did so anyway and kept emphasizing an irrelevant part of the ex girlfriend’s story: the race of the two men Mr. Martinez allegedly fought. But i t was fatal to any chance of a fundamentally fair sentencing hearing when the ex girlfriend claimed that after the fight Mr. Mart inez told her , “‘Those two n [*] s said they were going to rape you.’” Applicable here, “ [s]ome toxins can be deadly in small doses .” Buck v. Davis, 580 U.S. 100, 12122 (2017). A mistrial should have been declared, and a new sentencing proceeding held. This is so even without knowing there were two B lack jurors on the panel , one of them was “one of the holdouts ,” and she only came around to a death sentence after “discussions” with other jurors. No mistrial was granted, and Oklahoma treated the issue as evidentiary error “ cured ” by the instruction to disregard racial statements made after denial of the motion for mistrial . The Tenth Circuit knew there were two B lack people on the jury but left that out of its 28 U.S.C. § 2254(d)(1) analysis disposing of Martinez’s fair trial claim. It included and emphasized the judge’s futile jury instruct ion. The se questions arise: 1) May evidence be so unduly prejudic ial to “one juror” in a capital sentencing proceeding that it renders it fundamentally unfair, particularly in jurisdictions requiring juror unanimity? 2) Should courts discard the fiction a curative instruction can unring a bell when it comes to “especially pernicious” racial bias in capital sentencing?