worst case, you've destroyed this company & made worthless all the holsters they've sold to people so far.
Nice guilt trip. Sorry, its BS. Oh, of COURSE the ATF would NEVER notice the product, and issue a ruling, except for the fact that ONE GUY thinking of buying one asked a question?? No, not buying that for a minute.
HOWEVER, even if I did, the one to blame is NOT the guy asking the question (or, even the ATF). The one(s) to blame for "destroying the company" would be the ones running the company, for not getting ATF approval before making their first sale.
Seriously, if you plan to make a product that, at a glance, at least, seem very similar to something that is regulated/banned, if you go ahead and spend your (and other people's money) setting up production and marketing WITHOUT getting a valid legal ruling from the GOV that your product is legal, then you're either an idiot, or something worse.
WITH ATF approval, suitably documented, if the ATF changes it's ruling, you at least have the "acting in good faith" argument to take them to court with.