Outside of a distaste for his methods (and a truly vile appellation), we weren't very informative on the matter of the DSD. This video, which captures the Double Shotgun Dude in his native environs, should suffice to explain the matter in its entirety.
We learned today that the way people are dealing with this kind of opponent is to use the Javelin Glitch, which is just fucking fantastic.
The Javelin Glitch (a resolution for which is underway) is truly the ultimate in bullshit, and given the kind of crap they accept in the game proper it's got to be pretty bad if they're trying to patch it out. It is a mechanism by which a person can explode when you shoot them - not simply with a grenade, as the Martyrdom Deathstreak allows, but directing concussive force outward with the broad profile of an aerial bombardment. Imagine a pinata that includes not candy, by damnation. That's the Glitch in a nutshell.
CAN'T WAIT TO PLAY TONIGHT
(CW)TB