Earlier quoted context omitted.
I was fairly confident that buying a fully automatic firearm at a gun show was unlikely to be a matter of "ID + background check" as with buying a semi-automatic (or non-automatic) firearm. See links below (8 and 9 years old; the laws are unlikely to have become more liberal since then) for more info. My (perhaps inadequate) attempt to summarize the high points from those two sources: such purchases (in those states…
I suspect they were not using the right terminology; non-technical people don't know what the word "automatic" means, and some confuse "automatic rifle" for "assault rifle". You don't need an automatic rifle to inflict mass casualties (Orlando, Dallas) and even Western soldiers, I gather, rarely use full auto fire mode in battle. It's usually tactically unnecessary and empties the magazine in a few seconds.
I'm not saying ignorance makes them children, I'm saying ignorance makes their opinions unhelpful noise.