Here’s a video (in Spanish) with a lady from Sahuayo, singing a ballad about the kid and telling the story. At the end, it shows a statue of his body in death (apparently modeled after the famous statue of St. Cecilia’s disinterred body).
If you watch the movie For Greater Glory, they have combined a lot of characters to make things go faster. For example, “Lalo” is a composite of both Adan and Guillermo Galvez, the two neighbor boy brothers who rode off to join the Cristeros along with Jose.
But they’ve also combined stuff to avoid some of the weirder features from real life. There were a fair number of boys imprisoned in Sahuayo at the same time (many of whom were released when ransomed by their families – the soldiers were crooked as well as evil), and there were a fair number of witnesses to Jose’s last hours (as you’d expect when someone is being made an example of, and it’s a Mexican town where people watch what goes on). The dramatic martyrdom of a young kid like Sanchez, and the fact that a lot of people in town knew him, made his grave a place of veneration from the start.
But in the typical odd way of history, one of the witnessing boys, Enrique Amezcua, grew up to become a pious priest and founded a confraternity of priests. But another boy grew up to be that evil man, Maciel.
Of course Maciel did his best to milk his connection to a martyr, in the guise of promoting Sanchez’ cause of sainthood; and it seems that he wrote a lot about Sanchez in his autobiography. Of course he tried to take credit for the sainthood cause. He was a sociopath and a narcissist. Inserting himself into the center of every event — that’s what narcissists do.
But some of it may have been sincere. There’s a funny thing you’ll often notice about saints — like Jesus Himself, they tend to bring out the best and worst in people. Sometimes that includes psychopaths and sociopaths, perhaps because whatever is missing in them is often very present in saints. Or maybe it’s just part of the mysteries of mental illness and of evil.
But Sanchez himself was not a figment of Maciel’s imagination. The people of Mexico were the ones who promoted Sanchez’ cause, back when Maciel wasn’t running anything or writing any autobiographies. Sanchez was beatified after Maciel’s disgrace, after the beatification investigation had already dealt with Maciel’s dubious input, by Pope Benedict XVI. So they obviously had plenty of evidence without Maciel.
And so, it’s probably just as well that Maciel didn’t make it into the movie. Hollywood condensation of story has its advantages.