I don't mean to tell you your business, but I think you have to be very, very careful refusing service to a customer who's a) legally entitled to your service or product & b) not visibly impaired or disturbed. Suppose the customer in question is black, or LGBTQ. Your refusal of service could be easily misconstrued.

Either way, Walter refers to sellers who are legally entitled to sell legal products to people who are legally entitled to purchase them. It's one thing if a buyer displays problematic behavior. ATF form 4473 is designed to weed out such buyers. Obviously it doesn't always or often work.

It seems to me in this case attacking the seller (as opposed to the manufacturer) is relying on hindsight, which is always 20/20.

Don't get me wrong. I would have no problem restoring the assault weapons ban, reducing magazine capacity, requiring all sales be done via FPL, limiting bulk ammunition sales, strengthening red flag laws & even making Cali's ten-day waiting period universal. There used to be a 14-day waiting period on gun purchases, but that was only for the paperwork to clear. Now it's done much faster. But I'd initiate a true "cooling off" period on all firearm purchases.

In fact, my proposal for gun control, goes way beyond what anyone here, even Tim Wise, has suggested.

For all of that I just don't see blaming the seller as long as s/he did everything correctly.