Kai: If the vest was the correct type (low-cut and black) that black tie rig would be about as perfect as they come. Not bad as is, at least it's not colorful, but the pale high-cut vest doesn't say "evening". It's more of a morning suit type. In any case, enjoy your event.
In my book it is permissible to wear the more formal white waistcoat with black tie - although unusual. But I agree that if doing so, the cut should also be the deeper formal variety, and probably the fabric marcella - along with the shirt. Also, non-contrasting lapels are unusual. Love the peak.
Still, he looks splendid. Nice shine on those cordovan shoes too - not the obvious choice, but looks good. Here's to risk-taking and individuality. At least he's wearing socks and there are no jeans, cargo pants or "training shoes" involved. :)