Thuc said the novus ordo and repented of his traditionalism. The photos have been posted here many times.
So, the slanders continue. There's no evidence that he "repented" of Traditional Catholicism. At the end, he had been kidnapped by the Vietnamese Communist mob, and you can see in the picture of him at the very end that he appears to be in shock, not unlike how Cardinal Mindszenty appeared in a daze after his torture. We have absolutely no idea what happened to him after they took him into custody.
Prior to that, he did partially concelebrate the Novus Ordo Mass one time out of obedience to his bishop, and was apologetic of having done so when criticzed later for it.
But lack of actual evidence has never stopped you from hurling slander and calumny.