Can you think of any large scale regional or national emergency in the last 200 years where the military WASN'T involved? In my hometown the NG plowed the roads when the snow was REALLY bad.
As for the military participating in firearm confisation, remember that our oath is to the Constitution first and foremost. US Army units present in New Orleans, RA and NG both, refused to participate in the NO firearm confiscation. ALSO a federal court ruled the confisation illegal and unconstitutional... which sets a precident for future such actions.
Vigilance is admirable, but this scenario might be just a bit "tinfoil hat" at his point. If Billary gets into the White House (again) THEN I'll start to worry a bit.
Of course, if the Nat'l Guard and/or military were involved (the movement toward involving the military in domestic "emergencies" completely freaks me out),