Being old school, I'm not quite sure why DMWs attract quite so much opprobrium over any other type of sneaky manoeuvre -- the rules are quite clear about how a player should indicate they are eliminated, and one of the head refs specifically instructed us, "if the player does not have his hand on his head, shoot him." Natch. DMWs will come back to punish you, especially in a multiple point format where you'll be facing the same team again 2 minutes later. However, it is clear that DMWs are seen as more "unsportsmanlike" these days than they once were, and (while I never believed there was any point in creating rules specifically against them) I wouldn't try to argue the case for them to be acceptible -- it's always been a grey area, and it certainly doesn't make you any new friends.
On other points in the thread -- if a gun on field is illegal, that is entirely the player's fault and, whether intentional or not, warrants an appropriate penalty. It is not a ref's job to educate players, nor to provide technical assistance with their equipment.
And lastly back to the original point: it almost doesn't need to be said what sportsmen the Operation Sandbag guys are -- they have always been the good guys and it's heart-warming to read how they agreed to settle the tie, even though the rules would have put them through automatically by the arbitrary nature of alphabetical seeding.
Richard