Post hoc, ergo propter hoc

When Sheldon's mother suggests that her church group's prayers for his safety worked because he made it home, he says that she's using flawed reasoning. He says that argument is "post hoc, ergo propter hoc," using a Latin phrase which means "After this, therefore because of this." This line of faulty reasoning says that "Since that event followed this one, that event must have been caused by this one".