IIRC There was a lawsuit several years ago where someone sued the local law enforcement for failing to protect them. The resulting decision was that the police existed to protect the population as a whole but could not be held liable for failing to protect a particular individual.

I'd have no problem with patrols having a pad of forms stating "I have been advised to evacuate & choose not to do so. XYZ services may not be available until the order is lifted. The municipality is hereby immunized from all litigation. Signed _____" You have the option of leaving or signing the form.

It would be more effective for something like a hurricane where there's more warning. For the fires they'd probably have to be in an area that the fire hadn't reached yet unless the evac notice is sufficiently large.