I find it kinda fucked up that the liability is the main concern. If he's unfit to drive and is granted a license, he may die. If he's not granted a license, he may as well already be dead because he's never going to have any independence or opportunity anyway. The fact that this whole situation happened to begin with is unconscionable, and yet another example of why American suburbs are a fucking disaster.
As for the question of whether to give him one, only his doctor can answer that, obviously.