Every time I hear someone utter the words "Gun Show Loophole" I'll reply that first we should close the "David Gregory Loophole". This is a gift that will keep on giving. After all, it seems that NBC knew that displaying the magazine (well, possessing it, which they had to do to display it) was illegal before they taped the show. It's not like they were somehow caught by an obscure law - they knew about it and didn't care.
And Gregory gets to skate, because Liberals are so tribal that laws seemingly only apply to those they perceive as their enemies. That's why more gun laws should be opposed.