It's entirely possible that there could be something wrong with his, but my experience is that the foot clutch disengages both the transmission and PTO from being driven by the engine but the transmission and PTO are still mated together. Meaning the PTO and tires are either both spinning or neither spinning. The bush hog inertia absolutely drives the wheels of the tractor with the foot clutch pushed in.
But, like I had said earlier, the hand clutch/ range selector does let the PTO remain driven while clutching the transmission, and the bush hog does not push the tractor around. Maybe that is why it's listed as live on Tractor Data? It's actually a pretty good setup that woks well. I usually use 3rd gear to cut. In the thick stuff or for turns I use low range and lighter stuff or open areas I slide it into high which I think is called 5th. The range selector/ hand clutch can be operated on the fly and you can feather it just like a foot clutch. So you can ease up to something at a snails pace then add pressure up to the range selector's detent to speed on up to the full gear speed.