From the article:

The couple’s attorneys argued that Wisconsin law protects people from being charged with child abuse if they provide spiritual treatment for a child in lieu of medical assistance. They contended the law protects parents from criminal liability to the point of creating a substantial risk of death, making it difficult to know when a situation has become so serious that parents who stay with prayer healing become criminally liable.

If true, this is a seriously messed up legal situation. My proposal would be to give no deference at all to faith healing, making it legally equivalent to taking no action at all in the face of a child’s illness.