The Town Fair Tire decision prohibited Massachusetts from trying to get Town Fair from collecting sales tax from Mass residents.
When Healey takes TSUSA to court, they'll demand all of their sales records as part of the discovery process. Once they have that, I believe they'll cross reference those sales to use tax disclosures on tax returns filed.
They'll see that swatgig bought $1000 worth of ammo from TSUSA, then they'll see that swatgig did not disclose $1000 in out of state purchases in his Tax return (form 1). Now they come after swatgig for tax evasion, making me and all my friends fear buying from TSUSA again.
I don't know if the AG can legally do that or not. I don't see why a technicality like that would stop her.