Not really. Not sure how he'd carry a gun other than in a satchel. If he was going to conceal it given what he was wearing, he'd need a jacket.
Not necessarily. DM bought one of these inside-the-waistband holsters from ebay.
(picture from the listing, described as fitting small and pocket size 380 semi-autos).
From a web site on how to conceal a gun is this description and picture of a guy wearing a gun under a shirt:
"Just a plain white dress shirt is plenty of concealment if youve got an inside-the-waistband holster. Wear any sort of collared or uncollared shirt loose and untucked and youve got enough concealment to hide the grip of a handgun from casual observation."
The untucked clothing DM wore in the hangar walk video looks like it had lots of room to conceal a gun by this method.