Last fall, after Hood's defense team finally figured this out, they appealed his conviction; the Texas Court of Criminal Appeals (on which the judge had recently herself sat, making eight of the nine members her former colleagues) ruled 6-3 to uphold Hood's death sentence, as his lawyers had taken too long to bring up the illicit affair (which was kept very secret by its married participants), and that it may not have constituted a significant enough conflict of interest in any case.
No, really, this really happened, really. The Times' Adam Litpack characterizes the affair as "tawdry and sad." ("[Prosecutor]O’Connell did not seem especially romantic. Judge Holland testified that he once gave her a picture of a polar bear with a matching cup. Another time he gave her a chafing dish.") In her deposition, the Judge bristled at the revelation of the affair, and its damage to her personal reputation.