Dobson, yes the disk was free, but it was
highly likely that the staff was mis-informed about the distribution of that disk. (Lo and behold,
that actually was the case, some branches of Gamestop thought that you had to pre-order the game to get the demo.)
Either way, you can't just simply go: "Well, fuck you then." and TAKE it and walk off like that. Had you been in the wrong, you'd have been arrested for shoplifting.
Either way, I think that series of tweets sums up what Dobson is, as a person, he's arrogant enough to just up and take something without (I assume) speaking to a manager, too much of a weenie to face the consequences of his actions, and also tries to spin the story to make him seem like a misunderstood victim surrounded by people who don't 'get' him, when in fact he's a callous asshole who does what he wants when people try to tell him, "No."
Oh, nearly forgot: The same guy who is complaining when Gamestop chews him out for taking something that is free is also the same asshole who objects to his artwork (which was originally free to his Patrons until he changed the terms) being used without his 'permission'.