Chips Jr. was probably my all time favorite member here. Paint would get lost in pseudo-artsy BS; but Chips Jr. was like a ray of sunshine beaming through- the lone voice of level-headed sanity and reason.
Unconscious plagiarism is certainly possible, and I've done it myself. I've had to rewrite entire sections of stories after realizing what inspired them. The question of concept plagiarism (as opposed to text plagiarism) is a bit more complex.
"Don" is at present only available via Andromeda Spaceways (the issue as a whole is $5 at http://andromedaspaceways.com/shop/asm-71/). In a few months, when the exclusivity period expires, I'll be marketing it for reprint to some sites which will likely make it available for free, and if one of them buys it'll be on my author site.
But it's a good thing to pay for work if you want people to keep creating it, and IMO this issue is worth the cost.