To be fair, that's just what's on the deck. The trailer itself is part of the towed weight. So he's probably pulling more like 17,000 altogether.Not to rain on your parade here bud, but most half tons have an advertised 13k tow capacity.
So he's in 3/4 ton territory. But like I've said before, the new half tons are the one tons from decades ago. The new one tons are more like the 500 series from decades ago.
It's become a colloquialism, not an actual rating.