That’s an interesting point–but I’m not sure it jibes with Martha’s personality.
She’s spent her life a true believer in this church, and she sees everything through the lens of “is it good for this church or bad for this church?” and also the lens of “fuck all yall fuckers who are bad for this church I will hold a fucking grudge forever.” Her character is built on viciousness to her foes. I don’t see her looking for a way to keep an innocent man out of prison. Jud is bad for the church in her eyes, and she is terrible to him.
As for the resurrection vid making a murder charge impossible? You’re 100% right, but I’m not sure Martha will see it that way. She’s brilliant at twisty murder plots, but has a huge blind spot for religion. It’s more plausible to me that she thinks the cops will believe in a resurrection of a murdered man, and still charge the murderer, than that she wants them to conclude Wicks is a fraud in Mexico.
I can’t believe they didn’t just shoot that scene with no names — which could’ve simply kept open the possibility you mentioned, and also kept open the possibility that Blanc was playing not with Angela Lansbury but with Jessica Fletcher.