It's rare to see an opinion that reverses a criminal conviction based upon the failure of the U.S. to provide discovery. But it happens.
I must say that, in this case, I thank that Stever is probably guilty, and will be found as much even after the discovery is produced. But, like the panel, I'm not sure about that. Yeah, it looks like the big marijuana grow on his property had something to do with him. But it's at least worth considering that it was the product of someone else. And since the district court's ruling really did prevent Stever from arguing that it was someone else, that seems like reversible error to me.
Admittedly, I think that there may be some "strategery" going on here, and have a weak sense (though may be totally making this up) that the defense requested the discovery at issue not only because it might use it at trial, but also because producing it would be a big hassle for the government and thus incline them to plea the case out. But that's the nature of the beast.
Sometimes strategery works. As it does here.