The short answer is no.
You are attesting that your friend is NOT someone who, based on your past experience, should not have access to a firearm TODAY.
And by doing so you make no future prediction.
If he really is your friend, then be his reference.
I don't think they would do anything, but I also can't see into the future either. Really I'm just trying to generally discern whether this "Reference" is just a meaningless litmus test or a binding legal contract where I am tied to the person I give a reference for and any of their future actions.