be specific in detail - not allegorical or metaphorical
you're a relayer of info - not a writer....if you leave any room for it to be messed up in interpretation - it will be.
I think first off it would have to be KISS --Keep It Simple Stupid
Beyond that, I would have to tell him that no matter what he writes...some are going to believe it, some are not...and there is going to be a LOT of fighting over it. Perhaps I would suggest he not write it at all.