Here, in light of the translation and the DVD, there is substantial competent evidence to support the district court's findings. The district court had multiple opportunities to review the DVD and make judgments about the conditions of the interrogation. While the interrogation took place in relatively short segments-15 minutes, 40 minutes, 10 minutes-Solis-Munoz was left alone for long periods of time and had been in an interrogation room for approximately 7 hours. Although he never asked to communicate with the outside world, no offer was made to allow him to talk to anyone.
As I've noted before, I'm not sure this is the right standard of review. The judge doesn't really find that the statements are involuntary, only that the state failed to meet its burden of proving that the statements were voluntary. That's a negative finding with a different standard of review. But I suppose the result would be the same.
[Update: the state did not file a PR from the latest COA decision and the mandate issued on December 4, 2009.]