Yeah, that's my understanding. I've never seen it confirmed that they produce leopards, but I assume it has been? I was researching this a few years ago, and I had a hard time getting a straight answer back in 2010 or whatever.
It's still means you'd want to buy from a really reliable breeder. Because someone could totally sell you a regular pied for a lot more money as a "leopard pied", and you wouldn't know until you bred it. I guess that's what I find disconcerting.