What happened with Mahouka and Aldnoah v2 selling?

Either a big retailer messed up and reported all their BD sales as DVD, or someone at Oricon messed up, but the DVD/BD split reported in today's preliminary sales was clearly nonsense.
Vol 3 week 1: 2,112 DVD / 8,057 BD (79% BD)
Vol 4 week 1: 4,124 DVD / 5,255 BD (56% BD)
Vol 1 week 1: 1,013 DVD / 7,280 BD (88% BD)
Vol 2 week 1: 3,011 DVD / 4,248 BD (59% BD)
In other words, this would require over 2,000 people to have bought Aldnoah v1 on BD and then switched to DVD for v2. Needles to say, this never happens. Same deal with Mahouka, 2,000 or so people just switching formats suddenly four discs in.
it's clearly impossible, so someone obviously just made a mistake. Maybe it'll be corrected in the full list later this week. it's not the end of the world if they never fix it, because the *totals* we got are perfectly in line with what you'd expect for these volumes of these shows. But it's definitely weird!
Mahouka and Aldnoah *did* rank unexpectedly well on DVD in the daily rankings on pre-sale day (i.e. the day before street date when most internet retailers ship and report their sales). They were ahead of SAO and Monogatari, despite previous volumes selling significantly less on DVD than those ended up selling on DVD. So something had to have broken then, and maybe on release day as well.
Which implies to me that it has to be an internet retailer that reported sales incorrectly, not one of the B&Ms. This is expected anyway, because only a large internet retailer like Amazon (or maybe Aniplex+ given how hard they're pushing their own titles lately?) could swing things to the tune of ~2000 units. Animate could probably do it as well, but while these titles are storefront heavy, they're not the core Animate demographic shows. And it's more likely that one large internet retailer got messed up than half a dozen small specialty B&M retailers all messed up simultaneously.