If you can afford the toys, why not?
I do doubt he paid the NFA tax on the full auto stuff.
Nor market value with the military offering surplus (under GAO rules) to PD’s at discounts to get them off their books.
As an FFL/SOT he only has to pay the tax on Form 4 arms.
The article seems to claim he was dealing in Post-86 “Sample” arms which would not be (Unconstitutionally!) taxed.
The Fed Firearms Laws are almost too complex for an individual to fully understand and are constantly changing.
BATFE changes their “Rulings”, congress meddles, even Trump screwed up with his “Bump stock ban” EO.
I am sure there are very few here who really know the in’s and out’s of these allegations.