I'm sort of not surprised by their response. It reminds me a little bit about the "Honest Skin" debacle, where their first reason seemed to be to vehemently deny any wrongdoing before doing a real investigation. It may be a general cultural/customer service attitude type of thing, as I've even seen the Korean government run into trouble for a similar kind of "deny first, ask questions later" sort of response. It's the sort of response I would expect from arguing with a street vendor, but not from a big company, so that's pretty disappointing. I would actually feel like I would feel better if they responded that they didn't have any information yet and were doing a thorough investigation as to the source of the photos and would provide more information about their production process.

That said, a video like the one from MBD (would be awfully nice!) was produced by a TV show, so for them to produce a similar video like that without their own video production capabilities will take some time. If they outsource their mask production, it's also possible that the factory won't allow cameras inside.

Just to play devil's advocate, there are a lot of fakes out there, so could it be possible that the photos actually show the conditions in which the fakes are being produced? (Specifically speaking of Sulwhasoo, since it seems the Mediheal photos have been confirmed.) I don't want to rule out the possibility that the photos aren't actually from their facility.